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13 @chapter Tweaking output
15 This chapter discusses how to modify output. LilyPond is extremely
16 configurable; virtually every fragment of output may be changed.
21 * The Internals Reference manual::
22 * Appearance of objects::
23 * Placement of objects::
24 * Collisions of objects::
29 @section Tweaking basics
32 * Introduction to tweaks::
33 * Objects and interfaces::
34 * Naming conventions of objects and properties::
38 @node Introduction to tweaks
39 @subsection Introduction to tweaks
41 @q{Tweaking} is a LilyPond term for the various methods available
42 to the user for modifying the actions taken during interpretation
43 of the input file and modifying the appearance of the printed
44 output. Some tweaks are very easy to use; others are more
45 complex. But taken together the methods available for tweaking
46 permit almost any desired appearance of the printed music to be
49 In this section we cover the basic concepts required to understand
50 tweaking. Later we give a variety of ready-made commands which can
51 simply be copied to obtain the same effect in your own scores, and
52 at the same time we show how these commands may be constructed so
53 that you may learn how to develop your own tweaks.
55 Before starting on this Chapter you may wish to review the section
56 @ref{Contexts and engravers}, as Contexts, Engravers, and the
57 Properties contained within them are fundamental to understanding
58 and constructing Tweaks.
60 @node Objects and interfaces
61 @subsection Objects and interfaces
67 @cindex properties, object
68 @cindex object properties
70 @cindex object, layout
73 Tweaking involves modifying the internal operation and structures
74 of the LilyPond program, so we must first introduce some terms
75 which are used to describe those internal operations and
78 The term @q{Object} is a generic term used to refer to the
79 multitude of internal structures built by LilyPond during the
80 processing of an input file. So when a command like @code{\new
81 Staff} is encountered a new object of type @code{Staff} is
82 constructed. That @code{Staff} object then holds all the
83 properties associated with that particular staff, for example, its
84 name and its key signature, together with details of the engravers
85 which have been assigned to operate within that staff's context.
86 Similarly, there are objects to hold the properties of all other
87 contexts, such as @code{Voice} objects, @code{Score} objects,
88 @code{Lyrics} objects, as well as objects to represent all
89 notational elements such as bar lines,
90 note heads, ties, dynamics, etc. Every object has its own set of
93 Some types of object are given special names. Objects which represent
94 items of notation on the printed output such as note heads, stems,
95 slurs, ties, fingering, clefs, etc are called @q{Layout objects},
96 often known as @q{Graphical Objects}, or @q{Grobs} for short. These
97 are still objects in the generic sense above, and so they too all have
98 properties associated with them, such as their position, size, color,
101 Some layout objects are still more specialized. Phrasing slurs,
102 crescendo hairpins, ottava marks, and many other grobs are not
103 localized in a single place -- they have a starting point, an
104 ending point, and maybe other properties concerned with their
105 shape. Objects with an extended shape like these are called
108 It remains to explain what @q{Interfaces} are. Many objects, even
109 though they are quite different, share common features which need to
110 be processed in the same way. For example, all grobs have a color, a
111 size, a position, etc, and all these properties are processed in the
112 same way during LilyPond's interpretation of the input file. To
113 simplify these internal operations these common actions and properties
114 are grouped together in an object called a @code{grob-interface}.
115 There are many other groupings of common properties like this, each
116 one given a name ending in @code{interface}. In total there are over
117 100 such interfaces. We shall see later why this is of interest and
120 These, then, are the main terms relating to objects which we
121 shall use in this chapter.
123 @node Naming conventions of objects and properties
124 @subsection Naming conventions of objects and properties
126 @cindex naming conventions for objects
127 @cindex naming conventions for properties
128 @cindex objects, naming conventions
129 @cindex properties, naming conventions
131 We met some object naming conventions previously, in
132 @ref{Contexts and engravers}. Here for reference is a list
133 of the most common object and property types together with
134 the conventions for naming them and a couple of examples of
135 some real names. We have used @q{A} to stand for any capitalized
136 alphabetic character and @q{aaa} to stand for any number of
137 lower-case alphabetic characters. Other characters are used
140 @multitable @columnfractions .33 .33 .33
141 @headitem Object/property type
142 @tab Naming convention
145 @tab Aaaa or AaaaAaaaAaaa
146 @tab Staff, GrandStaff
148 @tab Aaaa or AaaaAaaaAaaa
151 @tab Aaaa_aaa_engraver
152 @tab Clef_engraver, Note_heads_engraver
154 @tab aaa-aaa-interface
155 @tab grob-interface, break-aligned-interface
156 @item Context Properties
157 @tab aaa or aaaAaaaAaaa
158 @tab alignAboveContext, skipBars
159 @item Layout Object Properties
160 @tab aaa or aaa-aaa-aaa
161 @tab direction, beam-thickness
164 As we shall see shortly, the properties of different types of
165 object are modified by different commands, so it is useful to
166 be able to recognize the type of object from the names of its
170 @node Tweaking methods
171 @subsection Tweaking methods
173 @cindex tweaking methods
175 @strong{\override command}
177 @cindex override command
178 @cindex override syntax
183 We have already met the commands @code{\set} and @code{\with}, used to
184 change the properties of @strong{contexts} and to remove and add
185 @strong{engravers}, in @ref{Modifying context properties}, and
186 @ref{Adding and removing engravers}. We now must meet some more
189 The command to change the properties of @strong{layout objects} is
190 @code{\override}. Because this command has to modify
191 internal properties deep within LilyPond its syntax is not
192 as simple as the commands you have met so far. It needs to
193 know precisely which property of which object in which context
194 has to be modified, and what its new value is to be. Let's see
197 The general syntax of this command is:
200 \override @var{Context}.@var{LayoutObject} #'@var{layout-property} =
205 This will set the property with the name @var{layout-property} of the
206 layout object with the name @var{LayoutObject}, which is a member of
207 the @var{Context} context, to the value @var{value}.
209 The @var{Context} can be omitted (and usually is) when the
210 required context is unambiguously implied and is one of lowest
211 level contexts, i.e., @code{Voice}, @code{ChordNames} or
212 @code{Lyrics}, and we shall omit it in many of the following
213 examples. We shall see later when it must be specified.
215 Later sections deal comprehensively with properties and their
216 values, but to illustrate the format and use of these commands
217 we shall use just a few simple properties and values which are
220 For now, don't worry about the @code{#'}, which must precede the
221 layout property, and the @code{#}, which must precede the value.
222 These must always be present in exactly this form. This is the
223 most common command used in tweaking, and most of the rest of
224 this chapter will be directed to presenting examples of how it is
225 used. Here is a simple example to change the color of the
228 @cindex color property, example
229 @cindex NoteHead, example of overriding
231 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
233 \override NoteHead #'color = #red
235 \override NoteHead #'color = #green
239 @strong{\revert command}
241 @cindex revert command
246 Once overridden, the property retains its new value until it is
247 overridden again or a @code{\revert} command is encountered.
248 The @code{\revert} command has the following syntax and causes
249 the value of the property to revert to its original default
250 value; note, not its previous value if several @code{\override}
251 commands have been issued.
254 \revert @var{Context}.@var{LayoutObject} #'@var{layout-property}
257 Again, just like @var{Context} in the @code{\override} command,
258 @var{Context} is often not needed. It will be omitted
259 in many of the following examples. Here we revert the color
260 of the note head to the default value for the final two notes:
262 @cindex color property, example
263 @cindex NoteHead, example of overriding
265 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
267 \override NoteHead #'color = #red
269 \override NoteHead #'color = #green
271 \revert NoteHead #'color
275 @strong{\once prefix}
280 Both the @code{\override} and the @code{\set} commands may be
281 prefixed by @code{\once}. This causes the following
282 @code{\override} or @code{\set} command to be effective only
283 during the current musical moment before the property reverts
284 back to its default value. Using the same example, we can
285 change the color of a single note like this:
287 @cindex color property, example
288 @cindex NoteHead, example of overriding
290 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
292 \once \override NoteHead #'color = #red
294 \once \override NoteHead #'color = #green
298 @strong{\overrideProperty command}
300 @cindex overrideProperty command
302 @funindex \overrideProperty
303 @funindex overrideProperty
305 There is another form of the override command,
306 @code{\overrideProperty}, which is occasionally required.
307 We mention it here for completeness, but for details see
308 @ruser{Difficult tweaks}.
309 @c Maybe explain in a later iteration -td
311 @strong{\tweak command}
313 @cindex tweak command
318 The final tweaking command which is available is @code{\tweak}.
319 This should be used to change the properties of objects which
320 occur at the same musical moment, such as the notes within a
321 chord. Using @code{\override} would affect all the notes
322 within a chord, whereas @code{\tweak} affects just the following
323 item in the input stream.
325 Here's an example. Suppose we wish to change the size of the
326 middle note head (the E) in a C major chord. Let's first see what
327 @code{\once \override} would do:
329 @cindex font-size property, example
330 @cindex NoteHead, example of overriding
332 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
334 \once \override NoteHead #'font-size = #-3
339 We see the override affects @emph{all} the note heads in the chord.
340 This is because all the notes of a chord occur at the same
341 @emph{musical moment}, and the action of @code{\once} is to
342 apply the override to all layout objects of the type specified
343 which occur at the same musical moment as the @code{\override}
346 The @code{\tweak} command operates in a different way. It acts
347 on the immediately following item in the input stream. However,
348 it is effective only on objects which are created directly from
349 the input stream, essentially note heads and articulations;
350 objects such as stems and accidentals are created later and
351 cannot be tweaked in this way. Furthermore, when it is applied
352 to note heads these @emph{must} be within a chord, i.e., within
353 single angle brackets, so to tweak a single note the @code{\tweak}
354 command must be placed inside single angle brackets with the
357 So to return to our example, the size of the middle note of
358 a chord would be changed in this way:
360 @cindex font-size property, example
361 @cindex @code{\tweak}, example
363 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
365 <c \tweak #'font-size #-3 e g>4
368 Note that the syntax of @code{\tweak} is different from that
369 of the @code{\override} command. Neither the context nor the
370 layout object should be specified; in fact, it would generate
371 an error to do so. These are both implied by the following
372 item in the input stream. Note also that an equals sign should
373 not be present. So the general syntax of the
374 @code{\tweak} command is simply
377 \tweak #'@var{layout-property} #@var{value}
380 A @code{\tweak} command can also be used to modify just one in
381 a series of articulations, as shown here:
383 @cindex color property, example
384 @cindex @code{\tweak}, example
386 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
388 -\tweak #'color #red ^Red
389 -\tweak #'color #green _Green
393 Note that the @code{\tweak} command must be preceded by an
394 articulation mark as if it were an articulation itself.
396 @cindex tuplets, nested
397 @cindex triplets, nested
398 @cindex bracket, tuplet
399 @cindex bracket, triplet
400 @cindex tuplet bracket
401 @cindex triplet bracket
403 @funindex TupletBracket
405 The @code{\tweak} command must also be used to change the
406 appearance of one of a set of nested tuplets which begin at the
407 same musical moment. In the following example, the long tuplet
408 bracket and the first of the three short brackets begin at the
409 same musical moment, so any @code{\override} command would apply
410 to both of them. In the example, @code{\tweak} is used to
411 distinguish between them. The first @code{\tweak} command
412 specifies that the long tuplet bracket is to be placed above the
413 notes and the second one specifies that the tuplet number is to be
414 printed in red on the first short tuplet bracket.
416 @cindex @code{\tweak}, example
417 @cindex direction property, example
418 @cindex color property, example
420 @lilypond[quote,ragged-right,verbatim,fragment,relative=2]
421 \tweak #'direction #up
424 \times 2/3 { c8[ c8 c8] }
425 \times 2/3 { c8[ c8 c8] }
426 \times 2/3 { c8[ c8 c8] }
430 If nested tuplets do not begin at the same moment, their
431 appearance may be modified in the usual way with
432 @code{\override} commands:
434 @cindex text property, example
435 @cindex tuplet-number function, example
436 @cindex transparent property, example
437 @cindex TupletNumber, example of overriding
439 @c NOTE Tuplet brackets collide if notes are high on staff
441 @lilypond[quote,ragged-right,verbatim,fragment,relative=1]
442 \times 2/3 { c8[ c c]}
443 \once \override TupletNumber
444 #'text = #tuplet-number::calc-fraction-text
448 \once \override TupletNumber #'transparent = ##t
449 \times 2/3 { c8[ c c] }
450 \times 2/3 { c8[ c c]}
457 @ruser{The tweak command}.
460 @node The Internals Reference manual
461 @section The Internals Reference manual
463 @cindex Internals Reference
466 * Properties of layout objects::
467 * Properties found in interfaces::
468 * Types of properties::
471 @node Properties of layout objects
472 @subsection Properties of layout objects
474 @cindex properties of layout objects
475 @cindex properties of grobs
476 @cindex grobs, properties of
477 @cindex layout objects, properties of
478 @cindex Internals Reference manual
480 Suppose you have a slur in a score which, to your mind,
481 appears too thin and you'd like to draw it a little heavier.
482 How do you go about doing this? You know from the statements
483 earlier about the flexibility of LilyPond that such a thing
484 should be possible, and you would probably guess that an
485 @code{\override} command would be needed. But is there a
486 heaviness property for a slur, and if there is, how might it
487 be modified? This is where the Internals Reference manual
488 comes in. It contains all the information you might need to
489 construct this and all other @code{\override} commands.
491 Before we look at the Internals Reference a word of warning.
492 This is a @strong{reference} document, which means there is
493 little or no explanation contained within it: its purpose is
494 to present information precisely and concisely. This
495 means it might look daunting at first sight. Don't worry!
496 The guidance and explanation presented here will enable you
497 to extract the information from the Internals Reference for
498 yourself with just a little practice.
500 @cindex override example
501 @cindex Internals Reference, example of using
502 @cindex @code{\addlyrics} example
504 Let's use a concrete example with a simple fragment of real
507 @lilypond[quote,verbatim,relative=2]
512 g[( e]) e d[( f]) a |
516 The man who feels love's sweet e -- mo -- tion
521 Suppose now that we decide we would like the slurs to be a
522 little heavier. Is this possible? The slur is certainly a
523 layout object, so the question is, @q{Is there a property
524 belonging to a slur which controls the heaviness?} To answer
525 this we must look in the Internals Reference, or IR for short.
527 The IR for the version of LilyPond you are using may be found
528 on the LilyPond website at @uref{http://lilypond.org}. Go to the
529 documentation page and click on the Internals Reference link.
530 For learning purposes you should use the standard HTML version,
531 not the @q{one big page} or the PDF. For the next few
532 paragraphs to make sense you will need to actually do this
535 Under the heading @strong{Top} you will see five links. Select
536 the link to the @emph{Backend}, which is where information about
537 layout objects is to be found. There, under the heading
538 @strong{Backend}, select the link to @emph{All layout objects}.
539 The page that appears lists all the layout objects used in your
540 version of LilyPond, in alphabetic order. Select the link to
541 Slur, and the properties of Slurs are listed.
543 An alternative way of finding this page is from the Notation
544 Reference. On one of the pages that deals with slurs you may find a
545 link to the Internals Reference. This link will take you directly to
546 this page, but if you have an idea about the name of the layout object
547 to be tweaked, it is easier to go straight to the IR and search there.
549 This Slur page in the IR tells us first that Slur objects are created
550 by the Slur_engraver. Then it lists the standard settings. Note
551 these are @strong{not} in alphabetic order. Browse down them looking
552 for a property that might control the heaviness of slurs, and you
556 @code{thickness} (number)
558 Line thickness, generally measured in @code{line-thickness}
561 This looks a good bet to change the heaviness. It tells us that
562 the value of @code{thickness} is a simple @emph{number},
563 that the default value is 1.2, and that the units are
564 in another property called @code{line-thickness}.
566 As we said earlier, there are few to no explanations in the IR,
567 but we already have enough information to try changing the
568 slur thickness. We see that the name of the layout object
569 is @code{Slur}, that the name of the property to change is
570 @code{thickness} and that the new value should be a number
571 somewhat larger than 1.2 if we are to make slurs thicker.
573 We can now construct the @code{\override} command by simply
574 substituting the values we have found for the names, omitting
575 the context. Let's use a very large value for the thickness
576 at first, so we can be sure the command is working. We get:
579 \override Slur #'thickness = #5.0
582 Don't forget the @code{#'} preceding the
583 property name and a @code{#} preceding the new value!
585 The final question is, @q{Where should this command be
586 placed?} While you are unsure and learning, the best
587 answer is, @q{Within the music, before the first slur and
588 close to it.} Let's do that:
590 @cindex Slur example of overriding
591 @cindex thickness property, example
593 @lilypond[quote,verbatim,relative=2]
597 % Increase thickness of all following slurs from 1.2 to 5.0
598 \override Slur #'thickness = #5.0
600 g[( e]) e d[( f]) a |
604 The man who feels love's sweet e -- mo -- tion
610 and we see that the slur is indeed heavier.
612 So this is the basic way of constructing @code{\override}
613 commands. There are a few more complications that we
614 shall meet in later sections, but you now know all the
615 essentials required to make up your own -- but you will
616 still need some practice. This is provided in the examples
619 @subheading Finding the context
621 @cindex context, finding
622 @cindex context, identifying correct
624 But first, what if we had needed to specify the Context?
625 What should it be? We could guess that slurs are in
626 the Voice context, as they are clearly closely associated
627 with individual lines of music, but can we be sure? To
628 find out, go back to the top of the IR page describing the
629 Slur, where it says @q{Slur objects are created by: Slur
630 engraver}. So slurs will be created in whichever context
631 the @code{Slur_engraver} is in. Follow the link to the
632 @code{Slur_engraver} page. At the very bottom it tells
633 us that @code{Slur_engraver} is part of five Voice contexts,
634 including the standard voice context, @code{Voice}, so our
635 guess was correct. And because @code{Voice} is one of the
636 lowest level contexts which is implied unambiguously by
637 the fact that we are entering notes, we can omit it in this
640 @subheading Overriding once only
642 @cindex overriding once only
643 @cindex once override
648 As you can see, @emph{all} the slurs are thicker in the final example
649 above. But what if we wanted just the first slur to be thicker? This
650 is achieved with the @code{\once} command. Placed immediately before
651 the @code{\override} command it causes it to change only the slur
652 which begins on the @strong{immediately following} note. If the
653 immediately following note does not begin a slur the command has no
654 effect at all -- it is not remembered until a slur is encountered, it
655 is simply discarded. So the command with @code{\once} must be
656 repositioned as follows:
658 @cindex Slur, example of overriding
659 @cindex thickness property, example
661 @lilypond[quote,verbatim,relative=2]
666 % Increase thickness of immediately following slur only
667 \once \override Slur #'thickness = #5.0
669 g[( e]) e d[( f]) a |
673 The man who feels love's sweet e -- mo -- tion
679 Now only the first slur is made heavier.
681 The @code{\once} command can also be used before the @code{\set}
684 @subheading Reverting
687 @cindex default properties, reverting to
692 Finally, what if we wanted just the first two slurs to be
693 heavier? Well, we could use two commands, each preceded by
694 @code{\once} placed immediately before each of the notes where
697 @cindex Slur, example of overriding
698 @cindex thickness property, example
700 @lilypond[quote,verbatim,relative=2]
705 % Increase thickness of immediately following slur only
706 \once \override Slur #'thickness = #5.0
708 % Increase thickness of immediately following slur only
709 \once \override Slur #'thickness = #5.0
710 g[( e]) e d[( f]) a |
714 The man who feels love's sweet e -- mo -- tion
720 or we could omit the @code{\once} command and use the @code{\revert}
721 command to return the @code{thickness} property to its default value
722 after the second slur:
724 @cindex Slur, example of overriding
725 @cindex thickness property, example
727 @lilypond[quote,verbatim,relative=2]
732 % Increase thickness of all following slurs from 1.2 to 5.0
733 \override Slur #'thickness = #5.0
736 % Revert thickness of all following slurs to default of 1.2
737 \revert Slur #'thickness
742 The man who feels love's sweet e -- mo -- tion
748 The @code{\revert} command can be used to return any property
749 changed with @code{\override} back to its default value.
750 You may use whichever method best suits what you want to do.
752 That concludes our introduction to the IR, and the basic
753 method of tweaking. Several examples follow in the later
754 sections of this Chapter, partly to introduce you to some of the
755 additional features of the IR, and partly to give you more
756 practice in extracting information from it. These examples will
757 contain progressively fewer words of guidance and explanation.
760 @node Properties found in interfaces
761 @subsection Properties found in interfaces
764 @cindex interface properties
765 @cindex properties in interfaces
767 Suppose now that we wish to print the lyrics in italics. What form of
768 @code{\override} command do we need to do this? We first look in the
769 IR page listing @q{All layout objects}, as before, and look for an
770 object that might control lyrics. We find @code{LyricText}, which
771 looks right. Clicking on this shows the settable properties for lyric
772 text. These include the @code{font-series} and @code{font-size}, but
773 nothing that might give an italic shape. This is because the shape
774 property is one that is common to all font objects, so, rather than
775 including it in every layout object, it is grouped together with other
776 similar common properties and placed in an @strong{Interface}, the
777 @code{font-interface}.
779 So now we need to learn how to find the properties of interfaces,
780 and to discover what objects use these interface properties.
782 Look again at the IR page which describes LyricText. At the bottom of
783 the page is a list of clickable interfaces which LyricText supports.
784 The list has several items, including @code{font-interface}. Clicking
785 on this brings up the properties associated with this interface, which
786 are also properties of all the objects which support it, including
789 Now we see all the user-settable properties which control fonts,
790 including @code{font-shape(symbol)}, where @code{symbol} can be
791 set to @code{upright}, @code{italics} or @code{caps}.
793 You will notice that @code{font-series} and @code{font-size} are also
794 listed there. This immediately raises the question: Why are the
795 common font properties @code{font-series} and @code{font-size} listed
796 under @code{LyricText} as well as under the interface
797 @code{font-interface} but @code{font-shape} is not? The answer is
798 that @code{font-series} and @code{font-size} are changed from their
799 global default values when a @code{LyricText} object is created, but
800 @code{font-shape} is not. The entries in @code{LyricText} then tell
801 you the values for those two properties which apply to
802 @code{LyricText}. Other objects which support @code{font-interface}
803 will set these properties differently when they are created.
805 Let's see if we can now construct the @code{\override} command
806 to change the lyrics to italics. The object is @code{LyricText},
807 the property is @code{font-shape} and the value is
808 @code{italic}. As before, we'll omit the context.
810 As an aside, although it is an important one, note that because the
811 values of @code{font-shape} are symbols they must be introduced with a
812 single apostrophe, @code{'}. That is why apostrophes are needed
813 before @code{thickness} in the earlier example and @code{font-shape}.
814 These are both symbols too. Symbols are then read internally by
815 LilyPond. Some of them are the names of properties, like
816 @code{thickness} or @code{font-shape}, others are used as values that
817 can be given to properties, like @code{italic}. Note the distinction
818 from arbitrary text strings, which would appear as @code{"a text
819 string"}; for more details about symbols and strings, see @ref{Scheme
822 Ok, so the @code{\override} command we need to print the lyrics
826 \override LyricText #'font-shape = #'italic
830 and this should be placed just in front of and close to the
831 lyrics which it should affect, like this:
833 @cindex font-shape property, example
834 @cindex italic, example
835 @cindex LyricText, example of overriding
836 @cindex @code{\addlyrics}, example
838 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
843 g[( e]) e d[( f]) a |
847 \override LyricText #'font-shape = #'italic
848 The man who feels love's sweet e -- mo -- tion
854 and the lyrics are all printed in italics.
856 @subheading Specifying the context in lyric mode
858 @cindex context, specifying in lyric mode
859 @cindex lyric mode, specifying context
861 In the case of lyrics, if you try specifying the context in the
862 format given earlier the command will fail. A syllable
863 entered in lyricmode is terminated by either a space,
864 a newline or a digit. All other characters are included
865 as part of the syllable. For this reason a space or newline
866 must appear before the terminating @code{@}} to prevent it being
867 included as part of the final syllable. Similarly,
868 spaces must be inserted before and after the
869 period or dot, @q{.}, separating the context name from the
870 object name, as otherwise the two names are run together and
871 the interpreter cannot recognize them. So the command should be:
874 \override Lyrics . LyricText #'font-shape = #'italic
877 @warning{In lyrics always leave whitespace between the final
878 syllable and the terminating brace.}
880 @warning{In overrides in lyrics always place spaces around
881 the dot between the context name and the object name.}
885 Learning Manual: @ref{Scheme tutorial}.
888 @node Types of properties
889 @subsection Types of properties
891 @cindex property types
893 So far we have seen two types of property: @code{number} and
894 @code{symbol}. To be valid, the value given to a property
895 must be of the correct type and obey the rules for that type.
896 The type of property is always shown in brackets after the
897 property name in the IR. Here is a list of the types you may
898 need, together with the rules for that type, and some examples.
899 You must always add a hash symbol, @code{#}, of course,
900 to the front of these values when they are entered in the
901 @code{\override} command.
903 @multitable @columnfractions .2 .45 .35
904 @headitem Property type
908 @tab Either True or False, represented by #t or #f
909 @tab @code{#t}, @code{#f}
910 @item Dimension (in staff space)
911 @tab A positive decimal number (in units of staff space)
912 @tab @code{2.5}, @code{0.34}
914 @tab A valid direction constant or its numerical equivalent (decimal
915 values between -1 and 1 are allowed)
916 @tab @code{LEFT}, @code{CENTER}, @code{UP},
919 @tab A positive whole number
920 @tab @code{3}, @code{1}
922 @tab A set of values separated by spaces, enclosed in parentheses
923 and preceded by an apostrophe
924 @tab @code{'(left-edge staff-bar)}, @code{'(1)},
925 @code{'(1.0 0.25 0.5)}
927 @tab Any valid markup
928 @tab @code{\markup @{ \italic "cresc." @}}
930 @tab A fraction of a whole note constructed with the
932 @tab @code{(ly:make-moment 1 4)},
933 @code{(ly:make-moment 3 8)}
935 @tab Any positive or negative decimal value
936 @tab @code{3.5}, @code{-2.45}
937 @item Pair (of numbers)
938 @tab Two numbers separated by a @q{space . space} and enclosed
939 in brackets preceded by an apostrophe
940 @tab @code{'(2 . 3.5)}, @code{'(0.1 . -3.2)}
942 @tab Any of the set of permitted symbols for that property,
943 preceded by an apostrophe
944 @tab @code{'italic}, @code{'inside}
946 @tab A procedure, or @code{#f} to cause no action
947 @tab @code{bend::print}, @code{ly:text-interface::print},
950 @tab A list of three items enclosed in parentheses and preceded
951 by apostrophe-hash, @code{'#}.
952 @tab @code{'#(#t #t #f)}
957 Learning Manual: @ref{Scheme tutorial}.
960 @node Appearance of objects
961 @section Appearance of objects
963 Let us now put what we have learned into practice with a few
964 examples which show how tweaks may be used to change the
965 appearance of the printed music.
968 * Visibility and color of objects::
970 * Length and thickness of objects::
973 @node Visibility and color of objects
974 @subsection Visibility and color of objects
976 In the educational use of music we might wish to print a score
977 with certain elements omitted as an exercise for the student,
978 who is required to supply them. As a simple example,
979 let us suppose the exercise is to supply the missing bar lines
980 in a piece of music. But the bar lines are normally inserted
981 automatically. How do we prevent them printing?
983 Before we tackle this, let us remember that object properties are
984 grouped in what are called @emph{interfaces} -- see @ref{Properties
985 found in interfaces}. This is simply to group together those
986 properties that may be used together to tweak a graphical object -- if
987 one of them is allowed for an object, so are the others. Some objects
988 then use the properties in some interfaces, others use them from other
989 interfaces. The interfaces which contain the properties used by a
990 particular grob are listed in the IR at the bottom of the page
991 describing that grob, and those properties may be viewed by looking at
994 We explained how to find information about grobs in @ref{Properties of
995 layout objects}. Using the same approach, we go to the IR to find the
996 layout object which prints bar lines. Going via @emph{Backend} and
997 @emph{All layout objects} we find there is a layout object called
998 @code{BarLine}. Its properties include two that control its
999 visibility: @code{break-visibility} and @code{stencil}. Barline also
1000 supports a number of interfaces, including the @code{grob-interface},
1001 where we find the @code{transparent} and the @code{color} properties.
1002 All of these can affect the visibility of bar lines (and, of course,
1003 by extension, many other layout objects too.) Let's consider each of
1008 @cindex stencil property
1010 This property controls the appearance of the bar lines by specifying
1011 the symbol (glyph) which should be printed. In common
1012 with many other properties, it can be set to print nothing by
1013 setting its value to @code{#f}. Let's try it, as before, omitting
1014 the implied Context, @code{Voice}:
1016 @cindex BarLine, example of overriding
1017 @cindex stencil property, example
1019 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1022 \override BarLine #'stencil = ##f
1024 g, a16 b8 c d4 e16 |
1029 The bar lines are still printed. What is wrong? Go back to the IR
1030 and look again at the page giving the properties of BarLine. At the
1031 top of the page it says @qq{Barline objects are created by:
1032 Bar_engraver}. Go to the @code{Bar_engraver} page. At the bottom it
1033 gives a list of Contexts in which the bar engraver operates. All of
1034 them are of the type @code{Staff}, so the reason the @code{\override}
1035 command failed to work as expected is because @code{Barline} is not in
1036 the default @code{Voice} context. If the context is specified
1037 wrongly, the command simply does not work. No error message is
1038 produced, and nothing is logged in the log file. Let's try correcting
1039 it by adding the correct context:
1041 @cindex BarLine, example of overriding
1042 @cindex stencil property, example
1044 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1047 \override Staff.BarLine #'stencil = ##f
1049 g, a16 b8 c d4 e16 |
1054 Now the bar lines have vanished.
1056 Note, though, that setting the @code{stencil} property to @code{#f}
1057 will cause errors when the dimensions of the object are required for
1058 correct processing. For example, errors will be generated if the
1059 @code{stencil} property of the @code{NoteHead} object is set to
1060 @code{#f}. If this is the case, you can instead use the
1061 @code{point-stencil} function, which sets the stencil to a object
1064 @lilypond[quote,verbatim,relative=2]
1067 \once \override NoteHead #'stencil = #point-stencil
1072 @subheading break-visibility
1074 @cindex break-visibility property
1076 We see from the @code{BarLine} properties in the IR that the
1077 @code{break-visibility} property requires a vector of three booleans.
1078 These control respectively whether bar lines are printed at the end of
1079 a line, in the middle of lines, and at the beginning of lines. For
1080 our example we want all bar lines to be suppressed, so the value we
1081 need is @code{'#(#f #f #f)}. Let's try that, remembering to include
1082 the @code{Staff} context. Note also that in writing this value we
1083 have @code{#'#} before the opening bracket. The @code{'#} is required
1084 as part of the value to introduce a vector, and the first @code{#} is
1085 required, as always, to precede the value itself in the
1086 @code{\override} command.
1088 @cindex BarLine, example of overriding
1089 @cindex break-visibility property, example
1091 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1094 \override Staff.BarLine #'break-visibility = #'#(#f #f #f)
1096 g, a16 b8 c d4 e16 |
1101 And we see this too removes all the bar lines.
1103 @subheading transparent
1105 @cindex transparent property
1106 @cindex transparency
1108 We see from the properties specified in the @code{grob-interface} page
1109 in the IR that the @code{transparent} property is a boolean. This
1110 should be set to @code{#t} to make the grob transparent. In this next
1111 example let us make the time signature invisible rather than the bar
1112 lines. To do this we need to find the grob name for the time
1113 signature. Back to the @q{All layout objects} page in the IR to find
1114 the properties of the @code{TimeSignature} layout object. This is
1115 produced by the @code{Time_signature_engraver} which you can check
1116 also lives in the @code{Staff} context and also supports the
1117 @code{grob-interface}. So the command to make the time signature
1120 @cindex TimeSignature, example of overriding
1121 @cindex transparent property, example
1123 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1126 \override Staff.TimeSignature #'transparent = ##t
1128 g, a16 b8 c d4 e16 |
1134 The time signature is gone, but this command leaves a gap where
1135 the time signature should be. Maybe this is what is wanted for
1136 an exercise for the student to fill it in, but in other
1137 circumstances a gap might be undesirable. To remove it, the
1138 stencil for the time signature should be set to @code{#f}
1141 @cindex TimeSignature, example of overriding
1142 @cindex stencil property, example
1144 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1147 \override Staff.TimeSignature #'stencil = ##f
1149 g, a16 b8 c d4 e16 |
1155 and the difference is obvious: setting the stencil to @code{#f}
1156 removes the object entirely; making the object @code{transparent}
1157 leaves it where it is, but makes it invisible.
1161 @cindex color property
1163 Finally let us try making the bar lines invisible by coloring
1164 them white. (There is a difficulty with this in that the
1165 white bar line may or may not blank out the staff lines where
1166 they cross. You may see in some of the examples below that this
1167 happens unpredictably. The details of why this is so and how to
1168 control it are covered in @ruser{Painting objects white}. But at
1169 the moment we are learning about color, so please just accept this
1170 limitation for now.)
1172 The @code{grob-interface} specifies that the
1173 color property value is a list, but there is no
1174 explanation of what that list should be. The list it
1175 requires is actually a list of values in internal units,
1176 but, to avoid having to know what these are, several ways
1177 are provided to specify colors. The first way is to use one
1178 of the @q{normal} colors listed in the first table in
1179 @ruser{List of colors}. To set the bar lines to white
1182 @cindex BarLine, example of overriding
1183 @cindex color property, example
1185 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1188 \override Staff.BarLine #'color = #white
1190 g, a16 b8 c d4 e16 |
1196 and again, we see the bar lines are not visible. Note that
1197 @emph{white} is not preceded by an apostrophe -- it is not
1198 a symbol, but a @emph{function}. When called, it provides
1199 the list of internal values required to set the color to
1200 white. The other colors in the normal list are functions
1201 too. To convince yourself this is working you might like
1202 to change the color to one of the other functions in the
1210 The second way of changing the color is to use the list of
1211 X11 color names in the second list in @ruser{List of colors}.
1212 However, these must be preceded by another function, which
1213 converts X11 color names into the list of internal values,
1214 @code{x11-color}, like this:
1216 @cindex BarLine, example of overriding
1217 @cindex color property, example
1219 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1222 \override Staff.BarLine #'color = #(x11-color 'white)
1224 g, a16 b8 c d4 e16 |
1230 Note that in this case the function @code{x11-color} takes
1231 a symbol as an argument, so the symbol must be preceded by
1232 an apostrophe and the two enclosed in brackets.
1239 There is yet a third function, one which converts RGB values into
1240 internal colors -- the @code{rgb-color} function. This takes
1241 three arguments giving the intensities of the red, green and
1242 blue colors. These take values in the range 0 to 1. So to
1243 set the color to red the value should be @code{(rgb-color 1 0 0)}
1244 and to white it should be @code{(rgb-color 1 1 1)}:
1246 @cindex BarLine, example of overriding
1247 @cindex color property, example
1249 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1252 \override Staff.BarLine #'color = #(rgb-color 1 1 1)
1254 g, a16 b8 c d4 e16 |
1259 Finally, there is also a grey scale available as part of the
1260 X11 set of colors. These range from black, @code{'grey0'},
1261 to white, @code{'grey100}, in steps of 1. Let's illustrate
1262 this by setting all the layout objects in our example to
1263 various shades of grey:
1265 @cindex StaffSymbol, example of overriding
1266 @cindex TimeSignature, example of overriding
1267 @cindex Clef, example of overriding
1268 @cindex NoteHead, example of overriding
1269 @cindex Stem, example of overriding
1270 @cindex BarLine, example of overriding
1271 @cindex color property, example
1272 @cindex x11-color, example of using
1274 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1277 \override Staff.StaffSymbol #'color = #(x11-color 'grey30)
1278 \override Staff.TimeSignature #'color = #(x11-color 'grey60)
1279 \override Staff.Clef #'color = #(x11-color 'grey60)
1280 \override Voice.NoteHead #'color = #(x11-color 'grey85)
1281 \override Voice.Stem #'color = #(x11-color 'grey85)
1282 \override Staff.BarLine #'color = #(x11-color 'grey10)
1284 g, a16 b8 c d4 e16 |
1290 Note the contexts associated with each of the layout objects.
1291 It is important to get these right, or the commands will not
1292 work! Remember, the context is the one in which the appropriate
1293 engraver is placed. The default context for engravers can be
1294 found by starting from the layout object, going from there to
1295 the engraver which produces it, and on the engraver page in the
1296 IR it tells you in which context the engraver will normally be
1300 @node Size of objects
1301 @subsection Size of objects
1303 @cindex changing size of objects
1304 @cindex size of objects
1305 @cindex objects, size of
1306 @cindex objects, changing size of
1308 Let us begin by looking again at the earlier example
1309 see @ref{Nesting music expressions}) which showed
1310 how to introduce a new temporary staff, as in an @rglos{ossia}.
1312 @cindex alignAboveContext property, example
1313 @cindex @code{\with}, example
1315 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1316 \new Staff ="main" {
1323 alignAboveContext = #"main" }
1331 Ossia are normally written without clef and time signature, and
1332 are usually printed slightly smaller than the main staff. We
1333 already know now how to remove the clef and time signature --
1334 we simply set the stencil of each to @code{#f}, as follows:
1336 @cindex alignAboveContext property, example
1337 @cindex @code{\with}, example
1338 @cindex stencil property, example
1339 @cindex Clef, example of overriding
1340 @cindex TimeSignature, example of overriding
1342 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1343 \new Staff ="main" {
1350 alignAboveContext = #"main"
1353 \override Staff.Clef #'stencil = ##f
1354 \override Staff.TimeSignature #'stencil = ##f
1364 where the extra pair of braces after the @code{\with} clause are
1365 required to ensure the enclosed overrides and music are applied
1368 But what is the difference between modifying the staff context by
1369 using @code{\with} and modifying the stencils of the clef and the
1370 time signature with \override? The main difference is that
1371 changes made in a @code{\with} clause are made at the time the
1372 context is created, and remain in force as the @strong{default}
1373 values for the duration of that context, whereas
1374 @code{\set} or @code{\override} commands embedded in the
1375 music are dynamic -- they make changes synchronized with
1376 a particular point in the music. If changes are unset or
1377 reverted using @code{\unset} or @code{\revert} they return to
1378 their default values, which will be the ones set in the
1379 @code{\with} clause, or if none have been set there, the normal
1382 Some context properties can be modified only in @code{\with} clauses.
1383 These are those properties which cannot sensibly be changed after the
1384 context has been created. @code{alignAboveContext} and its partner,
1385 @code{alignBelowContext}, are two such properties -- once the staff
1386 has been created its alignment is decided and it would make no sense
1387 to try to change it later.
1389 The default values of layout object properties can also be set
1390 in @code{\with} clauses. Simply use the normal @code{\override}
1391 command leaving out the context name, since this is unambiguously
1392 defined as the context which the @code{\with} clause is modifying.
1393 If fact, an error will be generated if a context is specified
1396 So we could replace the example above with
1398 @cindex alignAboveContext property, example
1399 @cindex @code{\with}, example
1400 @cindex Clef, example of overriding
1401 @cindex TimeSignature, example of overriding
1403 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1404 \new Staff ="main" {
1411 alignAboveContext = #"main"
1412 % Don't print clefs in this staff
1413 \override Clef #'stencil = ##f
1414 % Don't print time signatures in this staff
1415 \override TimeSignature #'stencil = ##f
1424 Finally we come to changing the size of layout objects.
1426 Some layout objects are created as glyphs selected from a typeface
1427 font. These include note heads, accidentals, markup, clefs, time
1428 signatures, dynamics and lyrics. Their size is changed by modifying
1429 the @code{font-size} property, as we shall shortly see. Other layout
1430 objects such as slurs and ties -- in general, spanner objects -- are
1431 drawn individually, so there is no @code{font-size} associated with
1432 them. These objects generally derive their size from the objects to
1433 which they are attached, so usually there is no need to change their
1434 size manually. Still other properties such as the length of stems and
1435 bar lines, thickness of beams and other lines, and the separation of
1436 staff lines all need to be modified in special ways.
1438 Returning to the ossia example, let us first change the font-size.
1439 We can do this in two ways. We can either change the size of the
1440 fonts of each object type, like @code{NoteHead}s with commands
1444 \override NoteHead #'font-size = #-2
1447 or we can change the size of all fonts by setting a special
1448 property, @code{fontSize}, using @code{\set}, or by including
1449 it in a @code{\with} clause (but without the @code{\set}).
1455 Both of these statements would cause the font size to be reduced
1456 by 2 steps from its previous value, where each
1457 step reduces or increases the size by approximately 12%.
1459 Let's try it in our ossia example:
1461 @cindex alignAboveContext property, example
1462 @cindex @code{\with}, example
1463 @cindex Clef, example of overriding
1464 @cindex TimeSignature, example of overriding
1465 @cindex fontSize property, example
1467 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1468 \new Staff ="main" {
1475 alignAboveContext = #"main"
1476 \override Clef #'stencil = ##f
1477 \override TimeSignature #'stencil = ##f
1478 % Reduce all font sizes by ~24%
1488 This is still not quite right. The note heads and flags are
1489 smaller, but the stems are too long in proportion and the
1490 staff lines are spaced too widely apart. These need to be
1491 scaled down in proportion to the font reduction. The next
1492 sub-section discusses how this is done.
1494 @node Length and thickness of objects
1495 @subsection Length and thickness of objects
1501 @cindex size, changing
1502 @cindex stem length, changing
1503 @cindex staff line spacing, changing
1505 Distances and lengths in LilyPond are generally measured in
1506 staff-spaces, the distance between adjacent lines in the staff,
1507 (or occasionally half staff spaces) while most @code{thickness}
1508 properties are measured in units of an internal property called
1509 @code{line-thickness.} For example, by default, the lines of
1510 hairpins are given a thickness of 1 unit of @code{line-thickness},
1511 while the @code{thickness} of a note stem is 1.3. Note, though,
1512 that some thickness properties are different; for example, the
1513 thickness of beams is measured in staff-spaces.
1515 So how are lengths to be scaled in proportion to the font size?
1516 This can be done with the help of a special function called
1517 @code{magstep} provided for exactly this purpose. It takes
1518 one argument, the change in font size (#-2 in the example above)
1519 and returns a scaling factor suitable for reducing other
1520 objects in proportion. It is used like this:
1522 @cindex alignAboveContext property, example
1523 @cindex @code{\with}, example
1524 @cindex Clef, example of overriding
1525 @cindex TimeSignature, example of overriding
1526 @cindex fontSize property, example
1527 @cindex StaffSymbol, example of overriding
1528 @cindex magstep function, example of using
1529 @cindex staff-space property, example
1530 @cindex stencil property, example
1532 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1533 \new Staff ="main" {
1540 alignAboveContext = #"main"
1541 \override Clef #'stencil = ##f
1542 \override TimeSignature #'stencil = ##f
1544 % Reduce stem length and line spacing to match
1545 \override StaffSymbol #'staff-space = #(magstep -2)
1555 Since the length of stems and many other length-related properties are
1556 always calculated relative to the value of the @code{staff-space}
1557 property these are automatically scaled down in length too. Note that
1558 this affects only the vertical scale of the ossia -- the horizontal
1559 scale is determined by the layout of the main music in order to remain
1560 synchronized with it, so it is not affected by any of these changes in
1561 size. Of course, if the scale of all the main music were changed in
1562 this way then the horizontal spacing would be affected. This is
1563 discussed later in the layout section.
1565 This, then, completes the creation of an ossia. The sizes and
1566 lengths of all other objects may be modified in analogous ways.
1568 For small changes in scale, as in the example above, the
1569 thickness of the various drawn lines such as bar lines,
1570 beams, hairpins, slurs, etc does not usually require global
1571 adjustment. If the thickness of any particular layout object
1572 needs to be adjusted this can be best achieved by overriding its
1573 @code{thickness} property. An example of changing the thickness
1574 of slurs was shown above in @ref{Properties of layout objects}.
1575 The thickness of all drawn objects (i.e., those not produced
1576 from a font) may be changed in the same way.
1579 @node Placement of objects
1580 @section Placement of objects
1583 * Automatic behavior::
1584 * Within-staff objects::
1585 * Outside-staff objects::
1589 @node Automatic behavior
1590 @subsection Automatic behavior
1592 @cindex within-staff objects
1593 @cindex outside-staff objects
1594 @cindex objects, within-staff
1595 @cindex objects, outside-staff
1597 There are some objects in musical notation that belong to
1598 the staff and there are other objects that should be
1599 placed outside the staff. These are called within-staff
1600 objects and outside-staff objects respectively.
1602 Within-staff objects are those that are located on the staff
1603 -- note heads, stems, accidentals, etc. The positions of
1604 these are usually fixed by the music itself -- they are
1605 vertically positioned on specific lines of the staff or are
1606 tied to other objects that are so positioned. Collisions of
1607 note heads, stems and accidentals in closely set chords are
1608 normally avoided automatically. There are commands and
1609 overrides which can modify this automatic behavior, as we
1612 Objects belonging outside the staff include things such as
1613 rehearsal marks, text and dynamic markings. LilyPond's rule for
1614 the vertical placement of outside-staff objects is to place them
1615 as close to the staff as possible but not so close that they
1616 collide with any other object. LilyPond uses the
1617 @code{outside-staff-priority} property to determine the order in
1618 which the objects should be placed, as follows.
1620 First, LilyPond places all the within-staff objects.
1621 Then it sorts the outside-staff objects according to their
1622 @code{outside-staff-priority}. The outside-staff objects are
1623 taken one by one, beginning with the object with the lowest
1624 @code{outside-staff-priority}, and placed so that they do not
1625 collide with any objects that have already been placed. That is,
1626 if two outside-staff grobs are competing for the same space, the
1627 one with the lower @code{outside-staff-priority} will be placed
1628 closer to the staff. If two objects have the same
1629 @code{outside-staff-priority} the one encountered first will be
1630 placed closer to the staff.
1632 In the following example all the markup texts have the same
1633 priority (since it is not explicitly set). Note that @q{Text3}
1634 is automatically positioned close to the staff again, nestling
1637 @cindex markup example
1639 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1646 Staves are also positioned, by default, as closely together as
1647 possible (subject to a minimum separation). If notes project
1648 a long way towards an adjacent staff they will force the
1649 staves further apart only if an overlap of the notation
1650 would otherwise occur. The following example demonstrates
1651 this @q{nestling} of the notes on adjacent staves:
1653 @lilypond[quote,ragged-right,verbatim]
1656 \relative c' { c a, }
1659 \relative c'''' { c a, }
1665 @node Within-staff objects
1666 @subsection Within-staff objects
1668 We have already seen how the commands @code{\voiceXXX} affect
1669 the direction of slurs, ties, fingering and
1670 everything else which depends on the direction of the stems.
1671 These commands are essential when writing polyphonic music to
1672 permit interweaving melodic lines to be distinguished.
1673 But occasionally it may be necessary to override this automatic
1674 behavior. This can be done for whole sections of music or even
1675 for an individual note. The property which controls this
1676 behavior is the @code{direction} property of each layout object.
1677 We first explain what this does, and then introduce a number of
1678 ready-made commands which avoid your having to code explicit
1679 overrides for the more common modifications.
1681 Some layout objects like slurs and ties curve, bend or point
1682 either up or down; others like stems and flags also move to
1683 right or left when they point up or down. This is controlled
1684 automatically when @code{direction} is set.
1691 The following example shows in bar 1 the default behavior of stems,
1692 with those on high notes pointing down and those on low notes pointing
1693 up, followed by four notes with all stems forced down, four notes with
1694 all stems forced up, and finally four notes reverted back to the
1697 @cindex Stem, example of overriding
1698 @cindex direction property, example
1700 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1702 \override Stem #'direction = #DOWN
1704 \override Stem #'direction = #UP
1706 \revert Stem #'direction
1710 Here we use the constants @code{DOWN} and @code{UP}.
1711 These have the values @code{-1} and @code{+1} respectively, and
1712 these numerical values may be used instead. The value @code{0}
1713 may also be used in some cases. It is simply treated as meaning
1714 @code{UP} for stems, but for some objects it means @q{center}.
1715 There is a constant, @code{CENTER} which has the value @code{0}.
1717 However, these explicit overrides are not usually used, as there are
1718 simpler equivalent predefined commands available. Here is a table of
1719 the commonest. The meaning of each is stated where it is not obvious.
1721 @multitable @columnfractions .2 .2 .25 .35
1726 @item @code{\arpeggioArrowDown}
1727 @tab @code{\arpeggioArrowUp}
1728 @tab @code{\arpeggioNormal}
1729 @tab Arrow is at bottom, at top, or no arrow
1730 @item @code{\dotsDown}
1732 @tab @code{\dotsNeutral}
1733 @tab Direction of movement to avoid staff lines
1734 @item @code{\dynamicDown}
1735 @tab @code{\dynamicUp}
1736 @tab @code{\dynamicNeutral}
1738 @item @code{\phrasingSlurDown}
1739 @tab @code{\phrasingSlurUp}
1740 @tab @code{\phrasingSlurNeutral}
1741 @tab Note: distinct from slur commands
1742 @item @code{\slurDown}
1744 @tab @code{\slurNeutral}
1746 @item @code{\stemDown}
1748 @tab @code{\stemNeutral}
1750 @item @code{\textSpannerDown}
1751 @tab @code{\textSpannerUp}
1752 @tab @code{\textSpannerNeutral}
1753 @tab Text entered as spanner is below/above staff
1754 @item @code{\tieDown}
1756 @tab @code{\tieNeutral}
1758 @item @code{\tupletDown}
1759 @tab @code{\tupletUp}
1760 @tab @code{\tupletNeutral}
1761 @tab Tuplets are below/above notes
1764 Note that these predefined commands may @strong{not} be
1765 preceded by @code{\once}. If you wish to limit the
1766 effect to a single note you must either use the equivalent
1767 @code{\once \override} command or use the predefined command
1768 followed after the affected note by the corresponding
1769 @code{\xxxNeutral} command.
1771 @subheading Fingering
1773 @cindex fingering, placement
1774 @cindex fingering, chords
1776 The placement of fingering on single notes can also be controlled
1777 by the @code{direction} property, but changing @code{direction}
1778 has no effect on chords. As we shall see, there are special
1779 commands which allow the fingering of individual notes
1780 of chords to be controlled, with the fingering being placed
1781 above, below, to the left or to the right of each note.
1783 First, here's the effect of @code{direction} on the fingering
1784 attached to single notes. The first bar shows the default
1785 behaviour, and the following two bars shows the effect of
1786 specifying @code{DOWN} and @code{UP}:
1788 @cindex Fingering, example of overriding
1789 @cindex direction property, example
1791 @lilypond[quote,verbatim,relative=2]
1793 \override Fingering #'direction = #DOWN
1795 \override Fingering #'direction = #UP
1799 However, overriding the @code{direction} property is not the
1800 easiest way of manually setting the fingering above or below
1801 the notes; using @code{_} or @code{^} instead of @code{-} before
1802 the fingering number is usually preferable. Here is the previous
1803 example using this method:
1805 @cindex fingering example
1807 @lilypond[quote,verbatim,relative=2]
1813 The @code{direction} property is ignored for chords, but the
1814 directional prefixes, @code{_} and @code{^} do work. By default,
1815 the fingering is automatically placed both above and below the
1816 notes of a chord, as shown:
1818 @cindex fingering example
1820 @lilypond[quote,verbatim,relative=2]
1827 but this may be overridden to manually force all or any of the
1828 individual fingering numbers above or below:
1830 @cindex fingering example
1832 @lilypond[quote,verbatim,relative=2]
1838 Even greater control over the placement of fingering of the
1839 individual notes in a chord is possible by using the
1840 @code{\set fingeringOrientations} command. The format of this
1844 @code{\set fingeringOrientations = #'([up] [left/right] [down])}
1848 @code{\set} is used because @code{fingeringOrientations} is a
1849 property of the @code{Voice} context, created and used by the
1850 @code{New_fingering_engraver}.
1852 The property may be set to a list of one to three values.
1853 It controls whether fingerings may be placed above (if
1854 @code{up} appears in the list), below (if @code{down} appears),
1855 to the left (if @code{left} appears, or to the right
1856 (if @code{right} appears). Conversely, if a location is not
1857 listed, no fingering is placed there. LilyPond takes these
1858 constraints and works out the best placement for the fingering
1859 of the notes of the following chords. Note that @code{left} and
1860 @code{right} are mutually exclusive -- fingering may be placed
1861 only on one side or the other, not both.
1863 @warning{To control the placement of the fingering of a single
1864 note using this command it is necessary to write it as a single
1865 note chord by placing angle brackets round it.}
1867 Here are a few examples:
1869 @cindex fingering example
1870 @cindex @code{\set}, example of using
1871 @cindex fingeringOrientations property, example
1873 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1874 \set fingeringOrientations = #'(left)
1876 < c-1 e-2 g-3 b-5 > 4
1877 \set fingeringOrientations = #'(left)
1879 < c-1 e-2 g-3 b-5 > 4
1880 \set fingeringOrientations = #'(up left down)
1882 < c-1 e-2 g-3 b-5 > 4
1883 \set fingeringOrientations = #'(up left)
1885 < c-1 e-2 g-3 b-5 > 4
1886 \set fingeringOrientations = #'(right)
1888 < c-1 e-2 g-3 b-5 > 4
1892 If the fingering seems a little crowded the @code{font-size}
1893 could be reduced. The default value can be seen from the
1894 @code{Fingering} object in the IR to be @code{-5}, so let's
1897 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1898 \override Fingering #'font-size = #-7
1899 \set fingeringOrientations = #'(left)
1901 < c-1 e-2 g-3 b-5 > 4
1902 \set fingeringOrientations = #'(left)
1904 < c-1 e-2 g-3 b-5 > 4
1905 \set fingeringOrientations = #'(up left down)
1907 < c-1 e-2 g-3 b-5 > 4
1908 \set fingeringOrientations = #'(up left)
1910 < c-1 e-2 g-3 b-5 > 4
1911 \set fingeringOrientations = #'(right)
1913 < c-1 e-2 g-3 b-5 > 4
1916 @node Outside-staff objects
1917 @subsection Outside-staff objects
1919 Outside-staff objects are automatically placed to avoid collisions.
1920 Objects with the lower value of the @code{outside-staff-priority}
1921 property are placed nearer to the staff, and other outside-staff
1922 objects are then raised as far as necessary to avoid collisions.
1923 The @code{outside-staff-priority} is defined in the
1924 @code{grob-interface} and so is a property of all layout objects.
1925 By default it is set to @code{#f} for all within-staff objects,
1926 and to a numerical value appropriate to each outside-staff object
1927 when the object is created. The following table shows
1928 the default numerical values for some of the commonest
1929 outside-staff objects which are, by default, placed in the
1930 @code{Staff} or @code{Voice} contexts.
1932 @multitable @columnfractions .3 .3 .3
1933 @headitem Layout Object
1935 @tab Controls position of:
1936 @item @code{MultiMeasureRestText}
1938 @tab Text over full-bar rests
1939 @item @code{TextScript}
1942 @item @code{OttavaBracket}
1944 @tab Ottava brackets
1945 @item @code{TextSpanner}
1948 @item @code{DynamicLineSpanner}
1950 @tab All dynamic markings
1951 @item @code{VoltaBracketSpanner}
1954 @item @code{TrillSpanner}
1956 @tab Spanning trills
1959 Here is an example showing the default placement of some of
1962 @cindex text spanner
1963 @cindex ottava bracket
1965 @funindex \startTextSpan
1966 @funindex startTextSpan
1967 @funindex \stopTextSpan
1968 @funindex stopTextSpan
1970 @cindex TextSpanner, example of overriding
1971 @cindex bound-details property, example
1973 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1974 % Set details for later Text Spanner
1975 \override TextSpanner #'(bound-details left text)
1976 = \markup { \small \bold Slower }
1977 % Place dynamics above staff
1979 % Start Ottava Bracket
1984 % Add Dynamic Line Spanner
1990 c\ff c \stopTextSpan
1991 % Stop Ottava Bracket
1996 This example also shows how to create Text Spanners --
1997 text with extender lines above a section of music. The
1998 spanner extends from the @code{\startTextSpan} command to
1999 the @code{\stopTextSpan} command, and the format of the
2000 text is defined by the @code{\override TextSpanner} command.
2001 For more details see @ruser{Text spanners}.
2003 It also shows how ottava brackets are created.
2005 @cindex tweaking bar number placement
2006 @cindex bar numbers, tweaking placement
2007 @cindex tweaking metronome mark placement
2008 @cindex metronome mark, tweaking placement
2009 @cindex tweaking rehearsal mark placement
2010 @cindex rehearsal marks, tweaking placement
2012 Note that bar numbers, metronome marks and rehearsal marks are not
2013 shown. By default these are created in the @code{Score} context and
2014 their @code{outside-staff-priority} is ignored relative to the layout
2015 objects which are created in the @code{Staff} context. If you wish to
2016 place bar numbers, metronome marks or rehearsal marks in accordance
2017 with the value of their @code{outside-staff-priority} the
2018 @code{Bar_number_engraver}, @code{Metronome_mark_engraver} or
2019 @code{Mark_engraver} respectively should be removed from the
2020 @code{Score} context and placed in the top @code{Staff} context. If
2021 this is done, these marks will be given the following default
2022 @code{outside-staff-priority} values:
2024 @multitable @columnfractions .3 .3
2025 @headitem Layout Object @tab Priority
2026 @item @code{RehearsalMark} @tab @code{1500}
2027 @item @code{MetronomeMark} @tab @code{1000}
2028 @item @code{BarNumber} @tab @code{ 100}
2031 If the default values of @code{outside-staff-priority} do not give you
2032 the placing you want, the priority of any of the objects may be
2033 overridden. Suppose we would like the ottava bracket to be placed
2034 below the text spanner in the example above. All we need to do is to
2035 look up the priority of @code{OttavaBracket} in the IR or in the
2036 tables above, and reduce it to a value lower than that of a
2037 @code{TextSpanner}, remembering that @code{OttavaBracket} is created
2038 in the @code{Staff} context:
2040 @cindex TextSpanner, example of overriding
2041 @cindex bound-details property, example
2043 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
2044 % Set details for later Text Spanner
2045 \override TextSpanner #'(bound-details left text)
2046 = \markup { \small \bold Slower }
2047 % Place dynamics above staff
2049 %Place following Ottava Bracket below Text Spanners
2050 \once \override Staff.OttavaBracket #'outside-staff-priority = #340
2051 % Start Ottava Bracket
2056 % Add Dynamic Line Spanner
2062 c\ff c \stopTextSpan
2063 % Stop Ottava Bracket
2068 @cindex slurs and outside-staff-priority
2069 @cindex slurs and articulations
2070 @cindex articulations and slurs
2072 Slurs by default are classed as within-staff objects, but
2073 they often appear above the staff if the notes to
2074 which they are attached are high on the staff. This can push
2075 outside-staff objects such as articulations too high, as the slur
2076 will be placed first. The @code{avoid-slur} property of the
2077 articulation can be set to @code{'inside} to bring the articulation
2078 inside the slur, but the @code{avoid-slur} property is effective
2079 only if the @code{outside-staff-priority} is also set to @code{#f}.
2080 Alternatively, the @code{outside-staff-priority} of the slur
2081 can be set to a numerical value to cause it to be placed along with
2082 other outside-staff objects according to that value. Here's an
2083 example showing the effect of the two methods:
2085 @lilypond[quote,verbatim,relative=2]
2086 c4( c^\markup\tiny\sharp d4.) c8
2088 \once \override TextScript #'avoid-slur = #'inside
2089 \once \override TextScript #'outside-staff-priority = ##f
2090 c^\markup\tiny\sharp d4.) c8
2091 \once \override Slur #'outside-staff-priority = #500
2092 c4( c^\markup\tiny\sharp d4.) c8
2095 Changing the @code{outside-staff-priority} can also be used to
2096 control the vertical placement of individual objects, although
2097 the results may not always be desirable. Suppose we would
2098 like @qq{Text3} to be placed above @qq{Text4} in the example
2099 under Automatic behavior, above (see @ref{Automatic behavior}).
2100 All we need to do is to look up the priority of @code{TextScript}
2101 in the IR or in the tables above, and increase the priority of
2102 @qq{Text3} to a higher value:
2104 @cindex TextScript, example of overriding
2105 @cindex outside-staff-priority property, example
2107 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2110 \once \override TextScript #'outside-staff-priority = #500
2115 This certainly lifts @qq{Text3} above @qq{Text4} but it also lifts it
2116 above @qq{Text2}, and @qq{Text4} now drops down. Perhaps this is not
2117 so good. What we would really like to do is to position all the
2118 annotation at the same distance above the staff. To do this, we
2119 clearly will need to space the notes out horizontally to make more
2120 room for the text. This is done using the @code{textLengthOn}
2123 @subheading \textLengthOn
2125 @cindex notes, spreading out with text
2127 @funindex \textLengthOn
2128 @funindex textLengthOn
2129 @funindex \textLengthOff
2130 @funindex textLengthOff
2132 By default, text produced by markup takes up no horizontal space
2133 as far as laying out the music is concerned. The @code{\textLengthOn}
2134 command reverses this behavior, causing the notes to be spaced
2135 out as far as is necessary to accommodate the text:
2137 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2138 \textLengthOn % Cause notes to space out to accommodate text
2145 The command to revert to the default behavior is
2146 @code{\textLengthOff}. Remember @code{\once} only works with
2147 @code{\override}, @code{\set}, @code{\revert} or @code{unset},
2148 so cannot be used with @code{\textLengthOn}.
2150 @cindex markup text, allowing collisions
2152 Markup text will also avoid notes which project above the staff.
2153 If this is not desired, the automatic displacement upwards may
2154 be turned off by setting the priority to @code{#f}. Here's an
2155 example to show how markup text interacts with such notes.
2157 @cindex TextScript, example of overriding
2158 @cindex outside-staff-priority property, example
2160 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2161 % This markup is short enough to fit without collision
2165 % This is too long to fit, so it is displaced upwards
2169 % Turn off collision avoidance
2170 \once \override TextScript #'outside-staff-priority = ##f
2174 % Turn off collision avoidance
2175 \once \override TextScript #'outside-staff-priority = ##f
2176 \textLengthOn % and turn on textLengthOn
2177 c,,2^"Long Text " % Spaces at end are honored
2182 @subheading Dynamics
2184 @cindex tweaking dynamics placement
2185 @cindex dynamics, tweaking placement
2187 Dynamic markings will normally be positioned beneath the
2188 staff, but may be positioned above with the @code{dynamicUp}
2189 command. They will be positioned vertically relative to the
2190 note to which they are attached, and will float below (or above)
2191 all within-staff objects such as phrasing slurs and bar numbers.
2192 This can give quite acceptable results, as this example
2195 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
2200 bes4.~\f\< \( bes4 bes8 des4\ff\> c16 bes\! |
2201 ees,2.~\)\mf ees4 r8 |
2204 However, if the notes and attached dynamics are close
2205 together the automatic placement will avoid collisions
2206 by displacing later dynamic markings further away, but this may
2207 not be the optimum placement, as this rather artificial example
2210 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2216 Should a similar situation arise in @q{real} music, it may be
2217 preferable to space out the notes a little further, so the dynamic
2218 markings can all fit at the same vertical distance from the staff. We
2219 were able to do this for markup text by using the @code{\textLengthOn}
2220 command, but there is no equivalent command for dynamic marks. So we
2221 shall have to work out how to do this using @code{\override} commands.
2223 @subheading Grob sizing
2226 @cindex sizing grobs
2228 First we must learn how grobs are sized. All grobs have a
2229 reference point defined within them which is used to position
2230 them relative to their parent object. This point in the grob
2231 is then positioned at a horizontal distance, @code{X-offset},
2232 and at a vertical distance, @code{Y-offset}, from its parent.
2233 The horizontal extent of the object is given by a pair of
2234 numbers, @code{X-extent}, which say where the left and right
2235 edges are relative to the reference point. The vertical extent
2236 is similarly defined by a pair of numbers, @code{Y-extent}.
2237 These are properties of all grobs which support the
2238 @code{grob-interface}.
2240 @cindex @code{extra-spacing-width}
2242 By default, outside-staff objects are given a width of zero so
2243 that they may overlap in the horizontal direction. This is done
2244 by the trick of adding infinity to the leftmost extent and
2245 minus infinity to the rightmost extent by setting the
2246 @code{extra-spacing-width} to @code{'(+inf.0 . -inf.0)}. So
2247 to ensure they do not overlap in the horizontal direction we
2248 must override this value of @code{extra-spacing-width} to
2249 @code{'(0 . 0)} so the true width shines through. This is
2250 the command to do this for dynamic text:
2253 \override DynamicText #'extra-spacing-width = #'(0 . 0)
2257 Let's see if this works in our previous example:
2259 @cindex DynamicText, example of overriding
2260 @cindex extra-spacing-width property, example
2262 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2264 \override DynamicText #'extra-spacing-width = #'(0 . 0)
2269 Well, it has certainly stopped the dynamic marks being
2270 displaced, but two problems remain. The marks should be
2271 spaced a little further apart and it would be better
2272 if they were all the same distance from the staff.
2273 We can solve the first problem easily. Instead of making
2274 the @code{extra-spacing-width} zero we could add a little
2275 more to it. The units are the space between two staff
2276 lines, so moving the left edge half a unit to the left and the
2277 right edge half a unit to the right should do it:
2279 @cindex DynamicText, example of overriding
2280 @cindex extra-spacing-width property, example
2282 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2284 % Extend width by 1 staff space
2285 \override DynamicText #'extra-spacing-width = #'(-0.5 . 0.5)
2290 This looks better, but maybe we would prefer the dynamic marks
2291 to be aligned along the same baseline rather than going up and
2292 down with the notes. The property to do this is
2293 @code{staff-padding} which is covered in the following section.
2296 @node Collisions of objects
2297 @section Collisions of objects
2301 * Fixing overlapping notation::
2302 * Real music example::
2305 @node Moving objects
2306 @subsection Moving objects
2308 @cindex moving overlapping objects
2309 @cindex moving colliding objects
2310 @cindex moving colliding grobs
2311 @cindex objects, moving colliding
2312 @cindex grobs, moving colliding
2314 This may come as a surprise, but LilyPond is not perfect. Some
2315 notation elements can overlap. This is unfortunate, but in fact
2316 rather rare. Usually the need to move objects is for clarity or
2317 aesthetic reasons -- they would look better with a little more
2318 or a little less space around them.
2320 There are three main approaches to resolving overlapping
2321 notation. They should be considered in the following order:
2325 The @strong{direction} of one of the overlapping objects may
2326 be changed using the predefined commands listed above for
2327 within-staff objects (see @ref{Within-staff objects}).
2328 Stems, slurs, beams, ties, dynamics, text and tuplets may be
2329 repositioned easily in this way. The limitation is that you
2330 have a choice of only two positions, and neither may be
2334 The @strong{object properties}, which LilyPond uses when positioning
2335 layout objects, may be modified using @code{\override}. The
2336 advantages of making changes to this type of property are (a) that
2337 some other objects will be moved automatically if necessary to make
2338 room and (b) the single override can apply to all instances of the
2339 same type of object. Such properties include:
2346 This has already been covered in some detail -- see
2347 @ref{Within-staff objects}.
2350 @code{padding}, @code{left-padding},
2351 @code{right-padding}, @code{staff-padding}
2354 @cindex left-padding property
2355 @cindex padding property
2356 @cindex right-padding property
2357 @cindex staff-padding property
2359 As an object is being positioned the value of its @code{padding}
2360 property specifies the gap that must be left between itself and the
2361 nearest edge of the object against which it is being positioned. Note
2362 that it is the @code{padding} value of the object @strong{being
2363 placed} that is used; the @code{padding} value of the object which is
2364 already placed is ignored. Gaps specified by @code{padding} can be
2365 applied to all objects which support the
2366 @code{side-position-interface}.
2368 Instead of @code{padding}, the placement of groups of accidentals
2369 is controlled by @code{left-padding} and @code{right-padding}.
2370 These properties are to be found in the @code{AccidentalPlacement}
2371 object which, note, lives in the @strong{staff} context. In the
2372 type-setting process the note heads are type-set first and then
2373 the accidentals, if any, are added to the left of the note heads
2374 using the @code{right-padding} property to determine the separation
2375 from the note heads. So only the @code{right-padding} property of the
2376 @code{AccidentalPlacement} object has any effect on the placement
2379 The @code{staff-padding} property is closely related to the
2380 @code{padding} property: @code{padding} controls the minimum amount of
2381 space between any object which supports the
2382 @code{side-position-interface} and the nearest other object (generally
2383 the note or the staff lines); @code{staff-padding} applies only to
2384 those objects which are always set outside the staff -- it controls
2385 the minimum amount of space that should be inserted between that
2386 object and the staff. Note that @code{staff-padding} has no effect on
2387 objects which are positioned relative to the note rather than the
2388 staff, even though it may be overridden without error for such objects
2389 -- it is simply ignored.
2391 To discover which padding property is required for the object you wish
2392 to reposition, you need to return to the IR and look up the object's
2393 properties. Be aware that the padding properties might not be located
2394 in the obvious object, so look in objects that appear to be related.
2396 All padding values are measured in staff spaces. For most
2397 objects, this value is set by default to be around 1.0 or less
2398 (it varies with each object). It may be overridden if a larger
2399 (or smaller) gap is required.
2402 @code{self-alignment-X}
2404 @cindex self-alignment-X property
2406 This property can be used to align the object to the left, to
2407 the right, or to center it with respect to the parent object's
2408 reference point. It may be used with all objects which support
2409 the @code{self-alignment-interface}. In general these are objects
2410 that contain text. The values are @code{LEFT}, @code{RIGHT}
2411 or @code{CENTER}. Alternatively, a numerical value between
2412 @code{-1} and @code{+1} may be specified, where @code{-1} is
2413 left-aligned, @code{+1} is right-aligned, and numbers in between
2414 move the text progressively from left-aligned to right-aligned.
2415 Numerical values greater than @code{1} may be specified to move
2416 the text even further to the left, or less than @code{-1} to
2417 move the text even further to the right. A change of @code{1}
2418 in the value corresponds to a movement of half the text's length.
2421 @code{extra-spacing-width}
2423 @cindex extra-spacing-width property
2425 This property is available for all objects which support the
2426 @code{item-interface}. It takes two numbers, the first is added
2427 to the leftmost extent and the second is added to the rightmost
2428 extent. Negative numbers move the edge to the left, positive to
2429 the right, so to widen an object the first number must be negative,
2430 the second positive. Note that not all objects honor both
2431 numbers. For example, the @code{Accidental} object only takes
2432 notice of the first (left edge) number.
2435 @code{staff-position}
2437 @cindex staff-position property
2439 @code{staff-position} is a property of the
2440 @code{staff-symbol-referencer-interface}, which is supported by
2441 objects which are positioned relative to the staff. It specifies
2442 the vertical position of the object relative to the center line
2443 of the staff in half staff-spaces. It is useful in resolving
2444 collisions between layout objects like multi-measure rests, ties
2445 and notes in different voices.
2450 @cindex force-hshift property
2452 Closely spaced notes in a chord, or notes occurring at the same
2453 time in different voices, are arranged in two, occasionally more,
2454 columns to prevent the note heads overlapping. These are called
2455 note columns, and an object called @code{NoteColumn} is created
2456 to lay out the notes in that column.
2458 The @code{force-hshift} property is a property of a @code{NoteColumn}
2459 (actually of the @code{note-column-interface}). Changing it permits a
2460 note column to be moved in units appropriate to a note column,
2461 viz. the note head width of the first voice note. It should be used
2462 in complex situations where the normal @code{\shiftOn} commands (see
2463 @ref{Explicitly instantiating voices}) do not resolve the note
2464 conflict. It is preferable to the @code{extra-offset} property for
2465 this purpose as there is no need to work out the distance in
2466 staff-spaces, and moving the notes into or out of a @code{NoteColumn}
2467 affects other actions such as merging note heads.
2472 Finally, when all else fails, objects may be manually repositioned
2473 relative to the staff center line vertically, or by displacing them by
2474 any distance to a new position. The disadvantages are that the
2475 correct values for the repositioning have to be worked out, often by
2476 trial and error, for every object individually, and, because the
2477 movement is done after LilyPond has placed all other objects, the user
2478 is responsible for avoiding any collisions that might ensue. But the
2479 main difficulty with this approach is that the repositioning values
2480 may need to be reworked if the music is later modified. The
2481 properties that can be used for this type of manual repositioning are:
2486 @cindex extra-offset property
2488 This property applies to any layout object supporting the
2489 @code{grob-interface}. It takes a pair of numbers which specify the
2490 extra displacement in the horizontal and vertical directions.
2491 Negative numbers move the object to the left or down. The units are
2492 staff-spaces. The extra displacement is made after the typesetting of
2493 objects is finished, so an object may be repositioned anywhere without
2494 affecting anything else.
2498 @cindex positions property
2500 This is most useful for manually adjusting the slope and height
2501 of beams, slurs, and tuplets. It takes a pair of numbers
2502 giving the position of the left and right ends of the beam, slur,
2503 etc. relative to the center line of the staff. Units are
2504 staff-spaces. Note, though, that slurs and phrasing slurs cannot
2505 be repositioned by arbitrarily large amounts. LilyPond first
2506 generates a list of possible positions for the slur and by default
2507 finds the slur that @qq{looks best}. If the @code{positions}
2508 property has been overridden the slur that is closest to the
2509 requested positions is selected from the list.
2514 A particular object may not have all of these properties.
2515 It is necessary to go to the IR to look up which properties
2516 are available for the object in question.
2518 Here is a list of the objects which are most likely to be
2519 involved in collisions, together with the name of the object which
2520 should be looked up in the IR in order to discover which properties
2521 should be used to move them.
2523 @multitable @columnfractions .5 .5
2524 @headitem Object type @tab Object name
2525 @item Articulations @tab @code{Script}
2526 @item Beams @tab @code{Beam}
2527 @item Dynamics (vertically) @tab @code{DynamicLineSpanner}
2528 @item Dynamics (horizontally) @tab @code{DynamicText}
2529 @item Fingerings @tab @code{Fingering}
2530 @item Rehearsal / Text marks @tab @code{RehearsalMark}
2531 @item Slurs @tab @code{Slur}
2532 @item Text e.g. @code{^"text"} @tab @code{TextScript}
2533 @item Ties @tab @code{Tie}
2534 @item Tuplets @tab @code{TupletBracket}
2538 @node Fixing overlapping notation
2539 @subsection Fixing overlapping notation
2541 Let's now see how the properties in the previous section can
2542 help to resolve overlapping notation.
2544 @subheading padding property
2547 @cindex fixing overlapping notation
2548 @cindex overlapping notation
2550 The @code{padding} property can be set to increase
2551 (or decrease) the distance between symbols that are printed
2552 above or below notes.
2554 @cindex Script, example of overriding
2555 @cindex padding property, example
2557 @lilypond[quote,fragment,relative=1,verbatim]
2559 \override Script #'padding = #3
2563 @cindex MetronomeMark, example of overriding
2564 @cindex padding property, example
2566 @lilypond[quote,fragment,relative=1,verbatim]
2567 % This will not work, see below:
2568 \override MetronomeMark #'padding = #3
2572 \override Score.MetronomeMark #'padding = #3
2577 Note in the second example how important it is to figure out what
2578 context handles a certain object. Since the @code{MetronomeMark}
2579 object is handled in the @code{Score} context, property changes in the
2580 @code{Voice} context will not be noticed. For more details, see
2581 @ruser{Modifying properties}.
2583 If the @code{padding} property of an object is increased when that
2584 object is in a stack of objects being positioned according to
2585 their @code{outside-staff-priority}, then that object and all
2586 objects outside it are moved.
2589 @subheading left-padding and right-padding
2591 @cindex left-padding property
2592 @cindex right-padding property
2594 The @code{right-padding} property affects the spacing between the
2595 accidental and the note to which it applies. It is not often
2596 required, but the following example shows one situation where it
2597 is needed. Suppose we wish to show a chord containing both
2598 a B-natural and a B-flat. To avoid ambiguity we would like to
2599 precede the notes with both a natural and a flat sign. Here
2600 are a few attempts to do this:
2602 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2608 None work, with the second two showing bad collisions between
2611 One way of achieving this is to override the accidental stencil
2612 with a markup containing the natural and flat symbols in the
2613 order we would like, like this:
2615 @cindex Accidental, example of overriding
2616 @cindex text property, example
2617 @cindex stencil property, example
2618 @cindex AccidentalPlacement, example of overriding
2619 @cindex right-padding property, example
2621 @lilypond[quote,ragged-right,verbatim]
2622 naturalplusflat = \markup { \natural \flat }
2624 \once \override Accidental
2625 #'stencil = #ly:text-interface::print
2626 \once \override Accidental #'text = #naturalplusflat
2627 \once \override Score.AccidentalPlacement #'right-padding = #1.5
2633 This necessarily uses an override for the accidental stencil which
2634 will not be covered until later. The stencil type must be a
2635 procedure, here changed to print the contents of the @code{text}
2636 property of @code{Accidental}, which itself is set to be a natural
2637 sign followed by a flat sign. These are then moved further away
2638 from the note head by overriding @code{right-padding}.
2642 @subheading staff-padding property
2644 @cindex aligning objects on a baseline
2645 @cindex objects, aligning on a baseline
2647 @code{staff-padding} can be used to align objects such as dynamics
2648 along a baseline at a fixed height above the staff, rather than at a
2649 height dependent on the position of the note to which they are
2650 attached. It is not a property of @code{DynamicText} but of
2651 @code{DynamicLineSpanner}. This is because the baseline should apply
2652 equally to @strong{all} dynamics, including those created as extended
2653 spanners. So this is the way to align the dynamic marks in the
2654 example taken from the previous section:
2656 @cindex DynamicText, example of overriding
2657 @cindex extra-spacing-width property, example
2658 @cindex DynamicLineSpanner, example of overriding
2659 @cindex staff-padding property, example
2661 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2663 % Extend width by 1 unit
2664 \override DynamicText #'extra-spacing-width = #'(-0.5 . 0.5)
2665 % Align dynamics to a base line 2 units above staff
2666 \override DynamicLineSpanner #'staff-padding = #2
2671 @subheading self-alignment-X property
2673 The following example shows how this can resolve the collision
2674 of a string fingering object with a note's stem by aligning the
2675 right edge with the reference point of the parent note:
2677 @cindex StringNumber, example of overriding
2678 @cindex self-alignment-X property, example
2680 @lilypond[quote,fragment,ragged-right,verbatim,relative=3]
2683 \once \override StringNumber #'self-alignment-X = #RIGHT
2687 @subheading staff-position property
2689 @cindex object collision within a staff
2691 Multimeasure rests in one voice can collide with notes in another.
2692 Since these rests are typeset centered between the bar lines, it
2693 would require significant effort for LilyPond to figure out which
2694 other notes might collide with it, since all the current collision
2695 handling between notes and between notes and rests is done only
2696 for notes and rests that occur at the same time. Here's an
2697 example of a collision of this type:
2699 @lilypond[quote,verbatim,fragment,ragged-right, relative=1]
2700 << {c c c c} \\ {R1} >>
2703 The best solution here is to move the multimeasure rest down, since
2704 the rest is in voice two. The default in @code{\voiceTwo} (i.e. in
2705 the second voice of a @code{<<@{...@} \\ @{...@}>>} construct) is that
2706 @code{staff-position} is set to -4 for MultiMeasureRest, so we need to
2707 move it, say, four half-staff spaces down to @code{-8}.
2709 @cindex MultiMeasureRest, example of overriding
2710 @cindex staff-position property, example
2712 @lilypond[quote,verbatim,fragment,ragged-right, relative=1]
2716 \override MultiMeasureRest #'staff-position = #-8
2721 This is better than using, for example, @code{extra-offset},
2722 because the ledger line above the rest is inserted automatically.
2724 @subheading extra-offset property
2726 @cindex positioning objects
2727 @cindex positioning grobs
2728 @cindex objects, positioning
2729 @cindex grobs, positioning
2731 The @code{extra-offset} property provides complete control over the
2732 positioning of an object both horizontally and vertically.
2734 In the following example, the second fingering is moved a little to
2735 the left, and 1.8 staff space downwards:
2737 @cindex Fingering, example of overriding
2738 @cindex extra-offset property, example
2740 @lilypond[quote,fragment,relative=1,verbatim]
2743 \once \override Fingering
2744 #'extra-offset = #'(-0.3 . -1.8)
2749 @subheading positions property
2751 @cindex controlling tuplets, slurs, phrasing slurs, and beams manually
2752 @cindex manually controlling tuplets, slurs, phrasing slurs, and beams
2753 @cindex tuplet beams, controlling manually
2754 @cindex slurs, controlling manually
2755 @cindex phrasing slurs, controlling manually
2756 @cindex beams, controlling manually
2758 The @code{positions} property allows the position and slope of
2759 tuplets, slurs, phrasing slurs and beams to be controlled manually.
2760 Here's an example which has an ugly phrasing slur due to its trying to
2761 avoid the slur on the acciaccatura.
2763 @lilypond[quote,verbatim,fragment,ragged-right,relative=1]
2764 r4 \acciaccatura e8\( d8 c ~c d c d\)
2768 We could simply move the phrasing slur above the notes, and this
2769 would be the preferred solution:
2771 @lilypond[quote,verbatim,fragment,ragged-right,relative=1]
2774 \acciaccatura e8\( d8 c ~c d c d\)
2778 But if there were some reason why this could not be done the
2779 other alternative would be to move the left end of the phrasing
2780 slur down a little using the @code{positions} property. This
2781 also resolves the rather nasty shape.
2783 @cindex PhrasingSlur, example of overriding
2784 @cindex positions property, example
2786 @lilypond[quote,verbatim,fragment,ragged-right,relative=1]
2788 \once \override PhrasingSlur #'positions = #'(-4 . -3)
2790 e8\( d8 c ~c d c d\)
2793 Here's a further example taken from the opening of the left-hand
2794 staff of Chopin's Prelude Op 28 No. 2. We see that the beam
2795 collides with the upper notes:
2797 @lilypond[quote,verbatim,fragment,ragged-right]
2800 << {b,8 ais, b, g,} \\ {e, g e, g} >>
2801 << {b,8 ais, b, g,} \\ {e, g e, g} >>
2806 This can be resolved by manually moving both ends of the beam
2807 up from their position at 2 staff-spaces above the center line to,
2810 @cindex Beam, example of overriding
2811 @cindex positions property, example
2813 @lilypond[quote,verbatim,fragment,ragged-right]
2817 \override Beam #'positions = #'(3 . 3)
2822 << {b,8 ais, b, g,} \\ {e, g e, g} >>
2827 Note that the override continues to apply in the first voice of
2828 the second block of quavers, but not to any of the beams in the
2831 @subheading force-hshift property
2833 @c FIXME: formatting stuff (ie not important right now IMO)
2834 @c @a nchor Chopin finally corrected TODOgp
2836 We can now see how to apply the final corrections to the Chopin
2837 example introduced at the end of @ref{I'm hearing Voices}, which
2838 was left looking like this:
2840 @lilypond[quote,verbatim,fragment,ragged-right]
2841 \new Staff \relative c'' {
2844 { c2 aes4. bes8 } \\
2856 The lower two notes of the first chord (i.e, those in the third voice)
2857 should not be shifted away from the note column of the higher two
2858 notes. To correct this we set @code{force-hshift}, which is a
2859 property of @code{NoteColumn}, of these notes to zero. The lower note
2860 of the second chord is best placed just to the right of the higher
2861 notes. We achieve this by setting @code{force-hshift} of this note to
2862 0.5, ie half a note head's width to the right of the note column of
2865 Here's the final result:
2867 @cindex NoteColumn, example of overriding
2868 @cindex force-hshift property, example
2870 @lilypond[quote,verbatim,fragment,ragged-right]
2871 \new Staff \relative c'' {
2874 { c2 aes4. bes8 } \\
2877 \once \override NoteColumn #'force-hshift = #0 <ees c>2
2878 \once \override NoteColumn #'force-hshift = #0.5 des2
2886 @node Real music example
2887 @subsection Real music example
2889 We end this section on Tweaks by showing the steps to be taken to
2890 deal with a tricky example which needs several tweaks to produce
2891 the desired output. The example has been deliberately chosen to
2892 illustrate the use of the Notation Reference to resolve unusual
2893 problems with notation. It is not representative of more usual
2894 engraving process, so please do not let these difficulties put
2895 you off! Fortunately, difficulties like these are not very common!
2897 The example is from Chopin's Première Ballade, Op. 23, bars 6 to
2898 9, the transition from the opening Lento to Moderato.
2899 Here, first, is what we want the output to look like, but to avoid
2900 over-complicating the example too much we have left out the
2901 dynamics, fingering and pedalling.
2903 @c The following should appear as music without code
2904 @c This example should not be indexed
2905 @lilypond[quote,ragged-right]
2906 rhMusic = \relative c'' {
2909 \once \override Tie #'staff-position = #3.5
2913 \mergeDifferentlyHeadedOn
2914 \mergeDifferentlyDottedOn
2915 bes2.^\markup {\bold "Moderato"} r8
2917 {c,8[ d fis bes a] | }
2919 % Reposition the c2 to the right of the merged note
2920 {c,8~ \once \override NoteColumn #'force-hshift = #1.0
2921 % Move the c2 out of the main note column so the merge will work
2924 % Stem on the d2 must be down to permit merging
2925 {s8 \stemDown \once \override Stem #'transparent = ##t d2}
2929 \mergeDifferentlyHeadedOff
2930 \mergeDifferentlyDottedOff
2934 lhMusic = \relative c' {
2936 <d g, d>1)\arpeggio |
2943 \new Staff = "RH" <<
2947 \new Staff = "LH" <<
2956 We note first that the right hand part in the third bar
2957 requires four voices. These are the five beamed eighth notes,
2958 the tied C, the half-note D which is merged with the eighth note
2959 D, and the dotted quarter note F-sharp, which is also merged with
2960 the eighth note at the same pitch. Everything else is in a single
2961 voice, so the easiest way is to introduce these four voices
2962 temporarily at the time they are needed. If you have forgotten
2963 how to do this, look at @ref{I'm hearing Voices}. Let us begin
2964 by entering the notes as two variables and setting up the staff
2965 structure in a score block, and see what LilyPond produces by
2968 @lilypond[quote,verbatim,ragged-right]
2969 rhMusic = \relative c'' {
2974 % Start polyphonic section of four voices
2976 {c,8 d fis bes a | }
2987 lhMusic = \relative c' {
2996 \new Staff = "RH" <<
3000 \new Staff = "LH" <<
3009 All the notes are right, but the appearance is far from satisfactory.
3010 The tie clashes with the change in time signature, the beaming in the
3011 third bar is wrong, the notes are not merged together, and several
3012 notation elements are missing. Let's first deal with the easier
3013 things. We can correct the beaming by inserting a beam manually, and
3014 we can easily add the left hand slur and the right hand phrasing slur,
3015 since these were all covered in the Tutorial. Doing this gives:
3017 @lilypond[quote,verbatim,ragged-right]
3018 rhMusic = \relative c'' {
3023 % Start polyphonic section of four voices
3025 {c,8[ d fis bes a] | }
3036 lhMusic = \relative c' {
3045 \new Staff = "RH" <<
3049 \new Staff = "LH" <<
3058 The first bar is now correct. The second bar contains an arpeggio and
3059 is terminated by a double bar line. How do we do these, as they have
3060 not been mentioned in this Learning Manual? This is where we need to
3061 turn to the Notation Reference. Looking up @q{arpeggio} and @q{bar
3062 line} in the index quickly shows us that an arpeggio is produced by
3063 appending @code{\arpeggio} to a chord, and a double bar line is
3064 produced by the @code{\bar "||"} command. That's easily done. We
3065 next need to correct the collision of the tie with the time signature.
3066 This is best done by moving the tie upwards. Moving objects was
3067 covered earlier in @ref{Moving objects}, which says that objects
3068 positioned relative to the staff can be moved by overriding their
3069 @code{staff-position} property, which is specified in half staff
3070 spaces relative to the center line of the staff. So the following
3071 override placed just before the first tied note would move the tie up
3072 to 3.5 half staff spaces above the center line:
3074 @code{\once \override Tie #'staff-position = #3.5}
3076 This completes bar two, giving:
3078 @lilypond[quote,verbatim,ragged-right]
3079 rhMusic = \relative c'' {
3081 \once \override Tie #'staff-position = #3.5
3086 % Start polyphonic section of four voices
3088 {c,8[ d fis bes a] | }
3099 lhMusic = \relative c' {
3101 <d g, d>1)\arpeggio |
3108 \new Staff = "RH" <<
3112 \new Staff = "LH" <<
3121 On to bar three and the start of the Moderato section. The tutorial
3122 showed how to add embolded text with the @code{\markup} command, so
3123 adding @q{Moderato} in bold is easy. But how do we merge notes in
3124 different voices together? This is where we need to turn to the
3125 Notation Reference for help. A search for @qq{merge} in the Notation
3126 Reference index quickly leads us to the commands for merging
3127 differently headed and differently dotted notes in @ruser{Collision
3128 resolution}. In our example we need to merge both types of note for
3129 the duration of the polyphonic section in bar 3, so using the
3130 information we find in the Notation Reference we add
3133 \mergeDifferentlyHeadedOn
3134 \mergeDifferentlyDottedOn
3138 to the start of that section and
3141 \mergeDifferentlyHeadedOff
3142 \mergeDifferentlyDottedOff
3148 @lilypond[quote,verbatim,ragged-right]
3149 rhMusic = \relative c'' {
3151 \once \override Tie #'staff-position = #3.5
3155 bes2.^\markup {\bold "Moderato"} r8
3156 \mergeDifferentlyHeadedOn
3157 \mergeDifferentlyDottedOn
3158 % Start polyphonic section of four voices
3160 {c,8[ d fis bes a] | }
3168 \mergeDifferentlyHeadedOff
3169 \mergeDifferentlyDottedOff
3173 lhMusic = \relative c' {
3175 <d g, d>1)\arpeggio |
3182 \new Staff = "RH" <<
3186 \new Staff = "LH" <<
3195 These overrides have merged the two F-sharp notes, but not the two
3196 on D. Why not? The answer is there in the same section in the
3197 Notation Reference -- notes being merged must have stems in
3198 opposite directions and two notes cannot be merged successfully if
3199 there is a third note in the same note column. Here the two D's
3200 both have upward stems and there is a third note -- the C. We know
3201 how to change the stem direction using @code{\stemDown}, and
3202 the Notation Reference also says how to move the C -- apply a shift
3203 using one of the @code{\shift} commands. But which one?
3204 The C is in voice two which has shift off, and the two D's are in
3205 voices one and three, which have shift off and shift on,
3206 respectively. So we have to shift the C a further level still
3207 using @code{\shiftOnn} to avoid it interfering with the two D's.
3208 Applying these changes gives:
3210 @cindex Tie, example of overriding
3211 @cindex staff-position property, example
3213 @lilypond[quote,verbatim,ragged-right]
3214 rhMusic = \relative c'' {
3216 \once \override Tie #'staff-position = #3.5
3220 bes2.^\markup {\bold "Moderato"} r8
3221 \mergeDifferentlyHeadedOn
3222 \mergeDifferentlyDottedOn
3223 % Start polyphonic section of four voices
3225 {c,8[ d fis bes a] | }
3227 % Move the c2 out of the main note column so the merge will work
3228 {c,8~ \shiftOnn c2 | }
3230 % Stem on the d2 must be down to permit merging
3231 {s8 \stemDown d2 | }
3235 \mergeDifferentlyHeadedOff
3236 \mergeDifferentlyDottedOff
3240 lhMusic = \relative c' {
3242 <d g, d>1)\arpeggio |
3249 \new Staff = "RH" <<
3253 \new Staff = "LH" <<
3262 Nearly there. Only two problems remain: The downward stem on the
3263 merged D should not be there, and the C would be better positioned
3264 to the right of the D's. We know how to do both of these from the
3265 earlier tweaks: we make the stem transparent, and move the C with
3266 the @code{force-hshift} property. Here's the final result:
3268 @cindex NoteColumn, example of overriding
3269 @cindex force-hshift property, example
3270 @cindex Stem, example of overriding
3271 @cindex transparent property, example
3273 @lilypond[quote,verbatim,ragged-right]
3274 rhMusic = \relative c'' {
3277 \once \override Tie #'staff-position = #3.5
3281 bes2.^\markup {\bold "Moderato"} r8
3282 \mergeDifferentlyHeadedOn
3283 \mergeDifferentlyDottedOn
3285 {c,8[ d fis bes a] | }
3287 % Reposition the c2 to the right of the merged note
3288 {c,8~ \once \override NoteColumn #'force-hshift = #1.0
3289 % Move the c2 out of the main note column so the merge will work
3292 % Stem on the d2 must be down to permit merging
3293 {s8 \stemDown \once \override Stem #'transparent = ##t d2}
3297 \mergeDifferentlyHeadedOff
3298 \mergeDifferentlyDottedOff
3302 lhMusic = \relative c' {
3304 <d g, d>1)\arpeggio |
3311 \new Staff = "RH" <<
3315 \new Staff = "LH" <<
3325 @node Further tweaking
3326 @section Further tweaking
3329 * Other uses for tweaks::
3330 * Using variables for tweaks::
3331 * Other sources of information::
3332 * Avoiding tweaks with slower processing::
3333 * Advanced tweaks with Scheme::
3336 @node Other uses for tweaks
3337 @subsection Other uses for tweaks
3339 @cindex transparent property, use of
3340 @cindex objects, making invisible
3341 @cindex removing objects
3342 @cindex objects, removing
3343 @cindex hiding objects
3344 @cindex objects, hiding
3345 @cindex invisible objects
3346 @cindex objects, invisible
3347 @cindex tying notes across voices
3349 @subheading Tying notes across voices
3351 The following example demonstrates how to connect notes in
3352 different voices using ties. Normally, only two notes in the
3353 same voice can be connected with ties. By using two voices,
3354 with the tied notes in one of them
3356 @lilypond[quote,fragment,relative=2]
3357 << { b8~ b8\noBeam }
3363 and blanking the first up-stem in that voice, the tie appears to
3366 @cindex Stem, example of overriding
3367 @cindex transparent property, example
3369 @lilypond[quote,fragment,relative=2,verbatim]
3372 \once \override Stem #'transparent = ##t
3380 To make sure that the just-blanked stem doesn't squeeze the tie
3381 too much, we can lengthen the stem by setting the
3382 @code{length} to @code{8},
3384 @lilypond[quote,fragment,relative=2,verbatim]
3387 \once \override Stem #'transparent = ##t
3388 \once \override Stem #'length = #8
3396 @subheading Simulating a fermata in MIDI
3398 @cindex stencil property, use of
3399 @cindex fermata, implementing in MIDI
3401 For outside-staff objects it is usually better to override the
3402 object's @code{stencil} property rather than its @code{transparent}
3403 property when you wish to remove it from the printed output.
3404 Setting the @code{stencil} property of an object to @code{#f} will
3405 remove that object entirely from the printed output. This means it
3406 has no effect on the placement of other objects placed relative to
3409 For example, if we wished to change the metronome setting in order
3410 to simulate a fermata in the MIDI output we would not want the
3411 metronome markings to appear in the printed output, and we would
3412 not want it to influence the spacing between the two systems or
3413 the positions of adjacent annotations on the staff. So setting
3414 its @code{stencil} property to @code{#f} would be the best way.
3415 We show here the effect of the two methods:
3417 @cindex MetronomeMark, example of overriding
3418 @cindex transparent property, example
3420 @lilypond[quote,verbatim,ragged-right]
3423 % Visible tempo marking
3426 \once \override Score.MetronomeMark #'transparent = ##t
3427 % Invisible tempo marking to lengthen fermata in MIDI
3430 % New tempo for next section
3439 @cindex MetronomeMark, example of overriding
3440 @cindex stencil property, example
3442 @lilypond[quote,verbatim,ragged-right]
3445 % Visible tempo marking
3448 \once \override Score.MetronomeMark #'stencil = ##f
3449 % Invisible tempo marking to lengthen fermata in MIDI
3452 % New tempo for next section
3462 Both methods remove the metronome mark which lengthens the fermata
3463 from the printed output, and both affect the MIDI timing as
3464 required, but the transparent metronome mark in the first line
3465 forces the following tempo indication too high while the
3466 second (with the stencil removed) does not.
3468 @node Using variables for tweaks
3469 @subsection Using variables for tweaks
3471 @cindex variables, using for tweaks
3472 @cindex using variables for tweaks
3473 @cindex tweaks, using variables for
3475 Override commands are often long and tedious to type, and they
3476 have to be absolutely correct. If the same overrides are to be
3477 used many times it may be worth defining variables to hold them.
3479 Suppose we wish to emphasize certain words in lyrics by printing
3480 them in bold italics. The @code{\italic} and @code{\bold}
3481 commands only work within lyrics if they are embedded, together with
3482 the word or words to be modified, within a @code{\markup} block,
3483 which makes them tedious to enter. The need to embed the words
3484 themselves prevents their use in simple variables. As an
3485 alternative can we use @code{\override} and @code{\revert} commands?
3488 @code{\override Lyrics . LyricText #'font-shape = #'italic}
3489 @code{\override Lyrics . LyricText #'font-series = #'bold}
3491 @code{\revert Lyrics . LyricText #'font-shape}
3492 @code{\revert Lyrics . LyricText #'font-series}
3495 These would also be extremely tedious to enter if there were many
3496 words requiring emphasis. But we @emph{can} define these as two
3497 variables and use those to bracket the words to be emphasized.
3498 Another advantage of using variables for these overrides is that
3499 the spaces around the dot are not necessary, since they are not
3500 being interpreted in @code{\lyricmode} directly. Here's an example
3501 of this, although in practice we would choose shorter names
3502 for the variables to make them quicker to type:
3504 @cindex LyricText, example of overriding
3505 @cindex font-shape property, example
3506 @cindex font-series property, example
3508 @lilypond[quote,verbatim]
3510 \override Lyrics.LyricText #'font-shape = #'italic
3511 \override Lyrics.LyricText #'font-series = #'bold
3514 \revert Lyrics.LyricText #'font-shape
3515 \revert Lyrics.LyricText #'font-series
3518 global = { \time 4/4 \partial 4 \key c \major}
3519 SopranoMusic = \relative c' { c4 | e4. e8 g4 g | a a g }
3520 AltoMusic = \relative c' { c4 | c4. c8 e4 e | f f e }
3521 TenorMusic = \relative c { e4 | g4. g8 c4. b8 | a8 b c d e4 }
3522 BassMusic = \relative c { c4 | c4. c8 c4 c | f8 g a b c4 }
3523 VerseOne = \lyrics { E -- | ter -- nal \emphasize Fa -- ther, \normal | strong to save, }
3524 VerseTwo = \lyricmode { O | \emphasize Christ, \normal whose voice the | wa -- ters heard, }
3525 VerseThree = \lyricmode { O | \emphasize Ho -- ly Spi -- rit, \normal | who didst brood }
3526 VerseFour = \lyricmode { O | \emphasize Tri -- ni -- ty \normal of | love and pow'r }
3532 \new Voice = "Soprano" { \voiceOne \global \SopranoMusic }
3533 \new Voice = "Alto" { \voiceTwo \AltoMusic }
3534 \new Lyrics \lyricsto "Soprano" { \VerseOne }
3535 \new Lyrics \lyricsto "Soprano" { \VerseTwo }
3536 \new Lyrics \lyricsto "Soprano" { \VerseThree }
3537 \new Lyrics \lyricsto "Soprano" { \VerseFour }
3541 \new Voice = "Tenor" { \voiceOne \TenorMusic }
3542 \new Voice = "Bass" { \voiceTwo \BassMusic }
3550 @node Other sources of information
3551 @subsection Other sources of information
3553 The Internals Reference documentation contains a lot of information
3554 about LilyPond, but even more information can be gathered by
3555 looking at the internal LilyPond files. To explore these, you must
3556 first find the directory appropriate to your system. The location
3557 of this directory depends (a) on whether you obtained LilyPond
3558 by downloading a precompiled binary from lilypond.org
3559 or whether you installed it from a package manager (i.e.
3560 distributed with Linux, or installed under fink or cygwin) or
3561 compiled it from source, and (b) on which operating system it is
3564 @strong{Downloaded from lilypond.org}
3570 @file{@var{INSTALLDIR}/lilypond/usr/share/lilypond/current/}
3575 @file{@var{INSTALLDIR}/LilyPond.app/Contents/Resources/share/lilypond/current/}
3576 by either @code{cd}-ing into this directory from the
3577 Terminal, or control-clicking on the LilyPond application and
3578 selecting @q{Show Package Contents}.
3582 Using Windows Explorer, navigate to
3583 @file{@var{INSTALLDIR}/LilyPond/usr/share/lilypond/current/}
3587 @strong{Installed from a package manager or compiled from source}
3590 @file{@var{PREFIX}/share/lilypond/@var{X.Y.Z}/}, where
3591 @var{PREFIX} is set by your package manager or @code{configure}
3592 script, and @var{X.Y.Z} is the LilyPond version number.
3596 Within this directory the two interesting subdirectories are
3599 @item @file{ly/} - contains files in LilyPond format
3600 @item @file{scm/} - contains files in Scheme format
3603 Let's begin by looking at some files in @file{ly/}.
3604 Open @file{ly/property-init.ly} in a text editor. The one
3605 you normally use for @code{.ly} files will be fine. This file
3606 contains the definitions of all the standard LilyPond predefined
3607 commands, such as @code{\stemUp} and @code{\slurDotted}. You will
3608 see that these are nothing more than definitions of variables
3609 containing one or a group of @code{\override} commands. For
3610 example, @code{/tieDotted} is defined to be:
3614 \override Tie #'dash-period = #0.75
3615 \override Tie #'dash-fraction = #0.1
3619 If you do not like the default values these predefined commands can
3620 be redefined easily, just like any other variable, at the
3621 head of your input file.
3623 The following are the most useful files to be found in
3626 @multitable @columnfractions .4 .6
3629 @item @file{ly/engraver-init.ly}
3630 @tab Definitions of engraver Contexts
3631 @item @file{ly/paper-defaults-init.ly}
3632 @tab Specifications of paper-related defaults
3633 @item @file{ly/performer-init.ly}
3634 @tab Definitions of performer Contexts
3635 @item @file{ly/property-init.ly}
3636 @tab Definitions of all common predefined commands
3637 @item @file{ly/spanner-init.ly}
3638 @tab Definitions of spanner-related predefined commands
3641 Other settings (such as the definitions of markup commands) are
3642 stored as @code{.scm} (Scheme) files. The Scheme programming
3643 language is used to provide a programmable interface into
3644 LilyPond internal operation. Further explanation of these files
3645 is currently outside the scope of this manual, as a knowledge of
3646 the Scheme language is required. Users should be warned that
3647 a substantial amount of technical knowledge or time is required
3648 to understand Scheme and these files (see @ref{Scheme tutorial}).
3650 If you have this knowledge, the Scheme files which may be of
3653 @multitable @columnfractions .4 .6
3656 @item @file{scm/auto-beam.scm}
3657 @tab Sub-beaming defaults
3658 @item @file{scm/define-grobs.scm}
3659 @tab Default settings for grob properties
3660 @item @file{scm/define-markup-commands.scm}
3661 @tab Specify all markup commands
3662 @item @file{scm/midi.scm}
3663 @tab Default settings for MIDI output
3664 @item @file{scm/output-lib.scm}
3665 @tab Settings that affect appearance of frets, colors,
3666 accidentals, bar lines, etc
3667 @item @file{scm/parser-clef.scm}
3668 @tab Definitions of supported clefs
3669 @item @file{scm/script.scm}
3670 @tab Default settings for articulations
3675 @node Avoiding tweaks with slower processing
3676 @subsection Avoiding tweaks with slower processing
3678 LilyPond can perform extra checks while it processes input files. These
3679 checks will take extra time to perform, but fewer manual tweaks
3680 may be required to obtain an acceptable result. If a text script
3681 or part of the lyrics extends over the margins these checks will
3682 compress that line of the score just enough to fit within the
3685 To be effective under all circumstances these checks must be enabled
3686 by placing the overrides in a Score @code{\with} block, rather than
3687 in-line in music, as follows:
3691 % Makes sure text scripts and lyrics are within the paper margins
3692 \override PaperColumn #'keep-inside-line = ##t
3693 \override NonMusicalPaperColumn #'keep-inside-line = ##t
3699 @node Advanced tweaks with Scheme
3700 @subsection Advanced tweaks with Scheme
3702 Although many things are possible with the @code{\override} and
3703 @code{\tweak} commands, an even more powerful way of modifying
3704 the action of LilyPond is available through a programmable
3705 interface to the LilyPond internal operation. Code written in
3706 the Scheme programming language can be incorporated directly in
3707 the internal operation of LilyPond. Of course, at least a basic
3708 knowledge of programming in Scheme is required to do this, and an
3709 introduction is provided in the @ref{Scheme tutorial}.
3711 As an illustration of one of the many possibilities, instead of
3712 setting a property to a constant it can be set to a Scheme
3713 procedure which is then called whenever that property is accessed
3714 by LilyPond. The property can then be set dynamically to a value
3715 determined by the procedure at the time it is called. In this
3716 example we color the note head in accordance with its position on
3719 @cindex x11-color function, example of using
3720 @cindex NoteHead, example of overriding
3721 @cindex color property, setting to Scheme procedure
3723 @lilypond[quote,verbatim,ragged-right]
3724 #(define (color-notehead grob)
3725 "Color the notehead according to its position on the staff."
3726 (let ((mod-position (modulo (ly:grob-property grob 'staff-position) 7)))
3728 ;; Return rainbow colors
3729 ((1) (x11-color 'red )) ; for C
3730 ((2) (x11-color 'orange )) ; for D
3731 ((3) (x11-color 'yellow )) ; for E
3732 ((4) (x11-color 'green )) ; for F
3733 ((5) (x11-color 'blue )) ; for G
3734 ((6) (x11-color 'purple )) ; for A
3735 ((0) (x11-color 'violet )) ; for B
3741 % Arrange to obtain color from color-notehead procedure
3742 \override NoteHead #'color = #color-notehead
3749 Some -- where o -- ver the Rain -- bow, way up high,
3753 Further examples showing the use of these programmable interfaces
3754 can be found in @ref{Tweaking with Scheme}.