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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 must now introduce 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 used 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 The @code{\override} command needed to print the lyrics in italics is:
825 \override LyricText #'font-shape = #'italic
829 This should be placed just in front of the lyrics we wish to affect,
832 @cindex font-shape property, example
833 @cindex italic, example
834 @cindex LyricText, example of overriding
835 @cindex @code{\addlyrics}, example
837 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
842 g[( e]) e d[( f]) a |
846 \override LyricText #'font-shape = #'italic
847 The man who feels love's sweet e -- mo -- tion
853 and the lyrics are all printed in italics.
855 @subheading Specifying the context in lyric mode
857 @cindex context, specifying in lyric mode
858 @cindex lyric mode, specifying context
860 In the case of lyrics, if you try specifying the context in the
861 format given earlier the command will fail. A syllable
862 entered in lyricmode is terminated by either a space,
863 a newline or a digit. All other characters are included
864 as part of the syllable. For this reason a space or newline
865 must appear before the terminating @code{@}} to prevent it being
866 included as part of the final syllable. Similarly,
867 spaces must be inserted before and after the
868 period or dot, @q{.}, separating the context name from the
869 object name, as otherwise the two names are run together and
870 the interpreter cannot recognize them. So the command should be:
873 \override Lyrics . LyricText #'font-shape = #'italic
876 @warning{In lyrics always leave whitespace between the final
877 syllable and the terminating brace.}
879 @warning{In overrides in lyrics always place spaces around
880 the dot between the context name and the object name.}
884 Learning Manual: @ref{Scheme tutorial}.
887 @node Types of properties
888 @subsection Types of properties
890 @cindex property types
892 So far we have seen two types of property: @code{number} and
893 @code{symbol}. To be valid, the value given to a property
894 must be of the correct type and obey the rules for that type.
895 The type of property is always shown in brackets after the
896 property name in the IR. Here is a list of the types you may
897 need, together with the rules for that type, and some examples.
898 You must always add a hash symbol, @code{#}, of course,
899 to the front of these values when they are entered in the
900 @code{\override} command.
902 @multitable @columnfractions .2 .45 .35
903 @headitem Property type
907 @tab Either True or False, represented by #t or #f
908 @tab @code{#t}, @code{#f}
909 @item Dimension (in staff space)
910 @tab A positive decimal number (in units of staff space)
911 @tab @code{2.5}, @code{0.34}
913 @tab A valid direction constant or its numerical equivalent (decimal
914 values between -1 and 1 are allowed)
915 @tab @code{LEFT}, @code{CENTER}, @code{UP},
918 @tab A positive whole number
919 @tab @code{3}, @code{1}
921 @tab A set of values separated by spaces, enclosed in parentheses
922 and preceded by an apostrophe
923 @tab @code{'(left-edge staff-bar)}, @code{'(1)},
924 @code{'(1.0 0.25 0.5)}
926 @tab Any valid markup
927 @tab @code{\markup @{ \italic "cresc." @}}
929 @tab A fraction of a whole note constructed with the
931 @tab @code{(ly:make-moment 1 4)},
932 @code{(ly:make-moment 3 8)}
934 @tab Any positive or negative decimal value
935 @tab @code{3.5}, @code{-2.45}
936 @item Pair (of numbers)
937 @tab Two numbers separated by a @q{space . space} and enclosed
938 in brackets preceded by an apostrophe
939 @tab @code{'(2 . 3.5)}, @code{'(0.1 . -3.2)}
941 @tab Any of the set of permitted symbols for that property,
942 preceded by an apostrophe
943 @tab @code{'italic}, @code{'inside}
945 @tab A procedure, or @code{#f} to cause no action
946 @tab @code{bend::print}, @code{ly:text-interface::print},
949 @tab A list of three items enclosed in parentheses and preceded
950 by apostrophe-hash, @code{'#}.
951 @tab @code{'#(#t #t #f)}
956 Learning Manual: @ref{Scheme tutorial}.
959 @node Appearance of objects
960 @section Appearance of objects
962 Let us now put what we have learned into practice with a few
963 examples which show how tweaks may be used to change the
964 appearance of the printed music.
967 * Visibility and color of objects::
969 * Length and thickness of objects::
972 @node Visibility and color of objects
973 @subsection Visibility and color of objects
975 In the educational use of music we might wish to print a score
976 with certain elements omitted as an exercise for the student,
977 who is required to supply them. As a simple example,
978 let us suppose the exercise is to supply the missing bar lines
979 in a piece of music. But the bar lines are normally inserted
980 automatically. How do we prevent them printing?
982 Before we tackle this, let us remember that object properties are
983 grouped in what are called @emph{interfaces} -- see @ref{Properties
984 found in interfaces}. This is simply to group together those
985 properties that may be used together to tweak a graphical object -- if
986 one of them is allowed for an object, so are the others. Some objects
987 then use the properties in some interfaces, others use them from other
988 interfaces. The interfaces which contain the properties used by a
989 particular grob are listed in the IR at the bottom of the page
990 describing that grob, and those properties may be viewed by looking at
993 We explained how to find information about grobs in @ref{Properties of
994 layout objects}. Using the same approach, we go to the IR to find the
995 layout object which prints bar lines. Going via @emph{Backend} and
996 @emph{All layout objects} we find there is a layout object called
997 @code{BarLine}. Its properties include two that control its
998 visibility: @code{break-visibility} and @code{stencil}. Barline also
999 supports a number of interfaces, including the @code{grob-interface},
1000 where we find the @code{transparent} and the @code{color} properties.
1001 All of these can affect the visibility of bar lines (and, of course,
1002 by extension, many other layout objects too.) Let's consider each of
1007 @cindex stencil property
1009 This property controls the appearance of the bar lines by specifying
1010 the symbol (glyph) which should be printed. In common
1011 with many other properties, it can be set to print nothing by
1012 setting its value to @code{#f}. Let's try it, as before, omitting
1013 the implied Context, @code{Voice}:
1015 @cindex BarLine, example of overriding
1016 @cindex stencil property, example
1018 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1021 \override BarLine #'stencil = ##f
1023 g, a16 b8 c d4 e16 |
1028 The bar lines are still printed. What is wrong? Go back to the IR
1029 and look again at the page giving the properties of BarLine. At the
1030 top of the page it says @qq{Barline objects are created by:
1031 Bar_engraver}. Go to the @code{Bar_engraver} page. At the bottom it
1032 gives a list of Contexts in which the bar engraver operates. All of
1033 them are of the type @code{Staff}, so the reason the @code{\override}
1034 command failed to work as expected is because @code{Barline} is not in
1035 the default @code{Voice} context. If the context is specified
1036 incorrectly, the command simply does not work. No error message is
1037 produced, and nothing is logged in the log file. Let's try correcting
1038 it by adding the correct context:
1040 @cindex BarLine, example of overriding
1041 @cindex stencil property, example
1043 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1046 \override Staff.BarLine #'stencil = ##f
1048 g, a16 b8 c d4 e16 |
1053 Now the bar lines have vanished.
1055 Note, though, that setting the @code{stencil} property to @code{#f}
1056 will cause errors when the dimensions of the object are required for
1057 correct processing. For example, errors will be generated if the
1058 @code{stencil} property of the @code{NoteHead} object is set to
1059 @code{#f}. If this is the case, you can instead use the
1060 @code{point-stencil} function, which sets the stencil to a object
1063 @lilypond[quote,verbatim,relative=2]
1066 \once \override NoteHead #'stencil = #point-stencil
1071 @subheading break-visibility
1073 @cindex break-visibility property
1075 We see from the @code{BarLine} properties in the IR that the
1076 @code{break-visibility} property requires a vector of three booleans.
1077 These control respectively whether bar lines are printed at the end of
1078 a line, in the middle of lines, and at the beginning of lines. For
1079 our example we want all bar lines to be suppressed, so the value we
1080 need is @code{'#(#f #f #f)}. Let's try that, remembering to include
1081 the @code{Staff} context. Note also that in writing this value we
1082 have @code{#'#} before the opening bracket. The @code{'#} is required
1083 as part of the value to introduce a vector, and the first @code{#} is
1084 required, as always, to precede the value itself in the
1085 @code{\override} command.
1087 @cindex BarLine, example of overriding
1088 @cindex break-visibility property, example
1090 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1093 \override Staff.BarLine #'break-visibility = #'#(#f #f #f)
1095 g, a16 b8 c d4 e16 |
1100 And we see this too removes all the bar lines.
1102 @subheading transparent
1104 @cindex transparent property
1105 @cindex transparency
1107 We see from the properties specified in the @code{grob-interface} page
1108 in the IR that the @code{transparent} property is a boolean. This
1109 should be set to @code{#t} to make the grob transparent. In this next
1110 example let us make the time signature invisible rather than the bar
1111 lines. To do this we need to find the grob name for the time
1112 signature. Back to the @q{All layout objects} page in the IR to find
1113 the properties of the @code{TimeSignature} layout object. This is
1114 produced by the @code{Time_signature_engraver} which you can check
1115 also lives in the @code{Staff} context and also supports the
1116 @code{grob-interface}. So the command to make the time signature
1119 @cindex TimeSignature, example of overriding
1120 @cindex transparent property, example
1122 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1125 \override Staff.TimeSignature #'transparent = ##t
1127 g, a16 b8 c d4 e16 |
1133 The time signature is gone, but this command leaves a gap where
1134 the time signature should be. Maybe this is what is wanted for
1135 an exercise for the student to fill it in, but in other
1136 circumstances a gap might be undesirable. To remove it, the
1137 stencil for the time signature should be set to @code{#f}
1140 @cindex TimeSignature, example of overriding
1141 @cindex stencil property, example
1143 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1146 \override Staff.TimeSignature #'stencil = ##f
1148 g, a16 b8 c d4 e16 |
1154 and the difference is obvious: setting the stencil to @code{#f}
1155 removes the object entirely; making the object @code{transparent}
1156 leaves it where it is, but makes it invisible.
1160 @cindex color property
1162 Finally let us try making the bar lines invisible by coloring
1163 them white. (There is a difficulty with this in that the
1164 white bar line may or may not blank out the staff lines where
1165 they cross. You may see in some of the examples below that this
1166 happens unpredictably. The details of why this is so and how to
1167 control it are covered in @ruser{Painting objects white}. But at
1168 the moment we are learning about color, so please just accept this
1169 limitation for now.)
1171 The @code{grob-interface} specifies that the
1172 color property value is a list, but there is no
1173 explanation of what that list should be. The list it
1174 requires is actually a list of values in internal units,
1175 but, to avoid having to know what these are, several ways
1176 are provided to specify colors. The first way is to use one
1177 of the @q{normal} colors listed in the first table in
1178 @ruser{List of colors}. To set the bar lines to white
1181 @cindex BarLine, example of overriding
1182 @cindex color property, example
1184 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1187 \override Staff.BarLine #'color = #white
1189 g, a16 b8 c d4 e16 |
1195 and again, we see the bar lines are not visible. Note that
1196 @emph{white} is not preceded by an apostrophe -- it is not
1197 a symbol, but a @emph{function}. When called, it provides
1198 the list of internal values required to set the color to
1199 white. The other colors in the normal list are functions
1200 too. To convince yourself this is working you might like
1201 to change the color to one of the other functions in the
1209 The second way of changing the color is to use the list of
1210 X11 color names in the second list in @ruser{List of colors}.
1211 However, these must be preceded by another function, which
1212 converts X11 color names into the list of internal values,
1213 @code{x11-color}, like this:
1215 @cindex BarLine, example of overriding
1216 @cindex color property, example
1218 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1221 \override Staff.BarLine #'color = #(x11-color 'white)
1223 g, a16 b8 c d4 e16 |
1229 Note that in this case the function @code{x11-color} takes
1230 a symbol as an argument, so the symbol must be preceded by
1231 an apostrophe and the two enclosed in brackets.
1238 There is yet a third function, one which converts RGB values into
1239 internal colors -- the @code{rgb-color} function. This takes
1240 three arguments giving the intensities of the red, green and
1241 blue colors. These take values in the range 0 to 1. So to
1242 set the color to red the value should be @code{(rgb-color 1 0 0)}
1243 and to white it should be @code{(rgb-color 1 1 1)}:
1245 @cindex BarLine, example of overriding
1246 @cindex color property, example
1248 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1251 \override Staff.BarLine #'color = #(rgb-color 1 1 1)
1253 g, a16 b8 c d4 e16 |
1258 Finally, there is also a grey scale available as part of the
1259 X11 set of colors. These range from black, @code{'grey0'},
1260 to white, @code{'grey100}, in steps of 1. Let's illustrate
1261 this by setting all the layout objects in our example to
1262 various shades of grey:
1264 @cindex StaffSymbol, example of overriding
1265 @cindex TimeSignature, example of overriding
1266 @cindex Clef, example of overriding
1267 @cindex NoteHead, example of overriding
1268 @cindex Stem, example of overriding
1269 @cindex BarLine, example of overriding
1270 @cindex color property, example
1271 @cindex x11-color, example of using
1273 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1276 \override Staff.StaffSymbol #'color = #(x11-color 'grey30)
1277 \override Staff.TimeSignature #'color = #(x11-color 'grey60)
1278 \override Staff.Clef #'color = #(x11-color 'grey60)
1279 \override Voice.NoteHead #'color = #(x11-color 'grey85)
1280 \override Voice.Stem #'color = #(x11-color 'grey85)
1281 \override Staff.BarLine #'color = #(x11-color 'grey10)
1283 g, a16 b8 c d4 e16 |
1289 Note the contexts associated with each of the layout objects.
1290 It is important to get these right, or the commands will not
1291 work! Remember, the context is the one in which the appropriate
1292 engraver is placed. The default context for engravers can be
1293 found by starting from the layout object, going from there to
1294 the engraver which produces it, and on the engraver page in the
1295 IR it tells you in which context the engraver will normally be
1299 @node Size of objects
1300 @subsection Size of objects
1302 @cindex changing size of objects
1303 @cindex size of objects
1304 @cindex objects, size of
1305 @cindex objects, changing size of
1307 Let us begin by looking again at the earlier example
1308 see @ref{Nesting music expressions}) which showed
1309 how to introduce a new temporary staff, as in an @rglos{ossia}.
1311 @cindex alignAboveContext property, example
1312 @cindex @code{\with}, example
1314 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1315 \new Staff ="main" {
1322 alignAboveContext = #"main" }
1330 Ossia are normally written without clef and time signature, and
1331 are usually printed slightly smaller than the main staff. We
1332 already know now how to remove the clef and time signature --
1333 we simply set the stencil of each to @code{#f}, as follows:
1335 @cindex alignAboveContext property, example
1336 @cindex @code{\with}, example
1337 @cindex stencil property, example
1338 @cindex Clef, example of overriding
1339 @cindex TimeSignature, example of overriding
1341 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1342 \new Staff ="main" {
1349 alignAboveContext = #"main"
1352 \override Staff.Clef #'stencil = ##f
1353 \override Staff.TimeSignature #'stencil = ##f
1363 where the extra pair of braces after the @code{\with} clause are
1364 required to ensure the enclosed overrides and music are applied
1367 But what is the difference between modifying the staff context by
1368 using @code{\with} and modifying the stencils of the clef and the
1369 time signature with \override? The main difference is that
1370 changes made in a @code{\with} clause are made at the time the
1371 context is created, and remain in force as the @strong{default}
1372 values for the duration of that context, whereas
1373 @code{\set} or @code{\override} commands embedded in the
1374 music are dynamic -- they make changes synchronized with
1375 a particular point in the music. If changes are unset or
1376 reverted using @code{\unset} or @code{\revert} they return to
1377 their default values, which will be the ones set in the
1378 @code{\with} clause, or if none have been set there, the normal
1381 Some context properties can be modified only in @code{\with} clauses.
1382 These are those properties which cannot sensibly be changed after the
1383 context has been created. @code{alignAboveContext} and its partner,
1384 @code{alignBelowContext}, are two such properties -- once the staff
1385 has been created its alignment is decided and it would make no sense
1386 to try to change it later.
1388 The default values of layout object properties can also be set
1389 in @code{\with} clauses. Simply use the normal @code{\override}
1390 command leaving out the context name, since this is unambiguously
1391 defined as the context which the @code{\with} clause is modifying.
1392 If fact, an error will be generated if a context is specified
1395 So we could replace the example above with
1397 @cindex alignAboveContext property, example
1398 @cindex @code{\with}, example
1399 @cindex Clef, example of overriding
1400 @cindex TimeSignature, example of overriding
1402 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1403 \new Staff ="main" {
1410 alignAboveContext = #"main"
1411 % Don't print clefs in this staff
1412 \override Clef #'stencil = ##f
1413 % Don't print time signatures in this staff
1414 \override TimeSignature #'stencil = ##f
1423 Finally we come to changing the size of layout objects.
1425 Some layout objects are created as glyphs selected from a typeface
1426 font. These include note heads, accidentals, markup, clefs, time
1427 signatures, dynamics and lyrics. Their size is changed by modifying
1428 the @code{font-size} property, as we shall shortly see. Other layout
1429 objects such as slurs and ties -- in general, spanner objects -- are
1430 drawn individually, so there is no @code{font-size} associated with
1431 them. These objects generally derive their size from the objects to
1432 which they are attached, so usually there is no need to change their
1433 size manually. Still other properties such as the length of stems and
1434 bar lines, thickness of beams and other lines, and the separation of
1435 staff lines all need to be modified in special ways.
1437 Returning to the ossia example, let us first change the font-size.
1438 We can do this in two ways. We can either change the size of the
1439 fonts of each object type, like @code{NoteHead}s with commands
1443 \override NoteHead #'font-size = #-2
1446 or we can change the size of all fonts by setting a special
1447 property, @code{fontSize}, using @code{\set}, or by including
1448 it in a @code{\with} clause (but without the @code{\set}).
1454 Both of these statements would cause the font size to be reduced
1455 by 2 steps from its previous value, where each
1456 step reduces or increases the size by approximately 12%.
1458 Let's try it in our ossia example:
1460 @cindex alignAboveContext property, example
1461 @cindex @code{\with}, example
1462 @cindex Clef, example of overriding
1463 @cindex TimeSignature, example of overriding
1464 @cindex fontSize property, example
1466 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1467 \new Staff ="main" {
1474 alignAboveContext = #"main"
1475 \override Clef #'stencil = ##f
1476 \override TimeSignature #'stencil = ##f
1477 % Reduce all font sizes by ~24%
1487 This is still not quite right. The note heads and flags are
1488 smaller, but the stems are too long in proportion and the
1489 staff lines are spaced too widely apart. These need to be
1490 scaled down in proportion to the font reduction. The next
1491 sub-section discusses how this is done.
1493 @node Length and thickness of objects
1494 @subsection Length and thickness of objects
1500 @cindex size, changing
1501 @cindex stem length, changing
1502 @cindex staff line spacing, changing
1504 Distances and lengths in LilyPond are generally measured in
1505 staff-spaces, the distance between adjacent lines in the staff,
1506 (or occasionally half staff spaces) while most @code{thickness}
1507 properties are measured in units of an internal property called
1508 @code{line-thickness.} For example, by default, the lines of
1509 hairpins are given a thickness of 1 unit of @code{line-thickness},
1510 while the @code{thickness} of a note stem is 1.3. Note, though,
1511 that some thickness properties are different; for example, the
1512 thickness of beams is measured in staff-spaces.
1514 So how are lengths to be scaled in proportion to the font size?
1515 This can be done with the help of a special function called
1516 @code{magstep} provided for exactly this purpose. It takes
1517 one argument, the change in font size (#-2 in the example above)
1518 and returns a scaling factor suitable for reducing other
1519 objects in proportion. It is used like this:
1521 @cindex alignAboveContext property, example
1522 @cindex @code{\with}, example
1523 @cindex Clef, example of overriding
1524 @cindex TimeSignature, example of overriding
1525 @cindex fontSize property, example
1526 @cindex StaffSymbol, example of overriding
1527 @cindex magstep function, example of using
1528 @cindex staff-space property, example
1529 @cindex stencil property, example
1531 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1532 \new Staff ="main" {
1539 alignAboveContext = #"main"
1540 \override Clef #'stencil = ##f
1541 \override TimeSignature #'stencil = ##f
1543 % Reduce stem length and line spacing to match
1544 \override StaffSymbol #'staff-space = #(magstep -2)
1554 Since the length of stems and many other length-related properties are
1555 always calculated relative to the value of the @code{staff-space}
1556 property these are automatically scaled down in length too. Note that
1557 this affects only the vertical scale of the ossia -- the horizontal
1558 scale is determined by the layout of the main music in order to remain
1559 synchronized with it, so it is not affected by any of these changes in
1560 size. Of course, if the scale of all the main music were changed in
1561 this way then the horizontal spacing would be affected. This is
1562 discussed later in the layout section.
1564 This, then, completes the creation of an ossia. The sizes and
1565 lengths of all other objects may be modified in analogous ways.
1567 For small changes in scale, as in the example above, the
1568 thickness of the various drawn lines such as bar lines,
1569 beams, hairpins, slurs, etc does not usually require global
1570 adjustment. If the thickness of any particular layout object
1571 needs to be adjusted this can be best achieved by overriding its
1572 @code{thickness} property. An example of changing the thickness
1573 of slurs was shown above in @ref{Properties of layout objects}.
1574 The thickness of all drawn objects (i.e., those not produced
1575 from a font) may be changed in the same way.
1578 @node Placement of objects
1579 @section Placement of objects
1582 * Automatic behavior::
1583 * Within-staff objects::
1584 * Outside-staff objects::
1588 @node Automatic behavior
1589 @subsection Automatic behavior
1591 @cindex within-staff objects
1592 @cindex outside-staff objects
1593 @cindex objects, within-staff
1594 @cindex objects, outside-staff
1596 There are some objects in musical notation that belong to
1597 the staff and there are other objects that should be
1598 placed outside the staff. These are called within-staff
1599 objects and outside-staff objects respectively.
1601 Within-staff objects are those that are located on the staff
1602 -- note heads, stems, accidentals, etc. The positions of
1603 these are usually fixed by the music itself -- they are
1604 vertically positioned on specific lines of the staff or are
1605 tied to other objects that are so positioned. Collisions of
1606 note heads, stems and accidentals in closely set chords are
1607 normally avoided automatically. There are commands and
1608 overrides which can modify this automatic behavior, as we
1611 Objects belonging outside the staff include things such as
1612 rehearsal marks, text and dynamic markings. LilyPond's rule for
1613 the vertical placement of outside-staff objects is to place them
1614 as close to the staff as possible but not so close that they
1615 collide with any other object. LilyPond uses the
1616 @code{outside-staff-priority} property to determine the order in
1617 which the objects should be placed, as follows.
1619 First, LilyPond places all the within-staff objects.
1620 Then it sorts the outside-staff objects according to their
1621 @code{outside-staff-priority}. The outside-staff objects are
1622 taken one by one, beginning with the object with the lowest
1623 @code{outside-staff-priority}, and placed so that they do not
1624 collide with any objects that have already been placed. That is,
1625 if two outside-staff grobs are competing for the same space, the
1626 one with the lower @code{outside-staff-priority} will be placed
1627 closer to the staff. If two objects have the same
1628 @code{outside-staff-priority} the one encountered first will be
1629 placed closer to the staff.
1631 In the following example all the markup texts have the same
1632 priority (since it is not explicitly set). Note that @q{Text3}
1633 is automatically positioned close to the staff again, nestling
1636 @cindex markup example
1638 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1645 Staves are also positioned, by default, as closely together as
1646 possible (subject to a minimum separation). If notes project
1647 a long way towards an adjacent staff they will force the
1648 staves further apart only if an overlap of the notation
1649 would otherwise occur. The following example demonstrates
1650 this @q{nestling} of the notes on adjacent staves:
1652 @lilypond[quote,ragged-right,verbatim]
1655 \relative c' { c a, }
1658 \relative c'''' { c a, }
1664 @node Within-staff objects
1665 @subsection Within-staff objects
1667 We have already seen how the commands @code{\voiceXXX} affect
1668 the direction of slurs, ties, fingering and
1669 everything else which depends on the direction of the stems.
1670 These commands are essential when writing polyphonic music to
1671 permit interweaving melodic lines to be distinguished.
1672 But occasionally it may be necessary to override this automatic
1673 behavior. This can be done for whole sections of music or even
1674 for an individual note. The property which controls this
1675 behavior is the @code{direction} property of each layout object.
1676 We first explain what this does, and then introduce a number of
1677 ready-made commands which avoid your having to code explicit
1678 overrides for the more common modifications.
1680 Some layout objects like slurs and ties curve, bend or point
1681 either up or down; others like stems and flags also move to
1682 right or left when they point up or down. This is controlled
1683 automatically when @code{direction} is set.
1690 The following example shows in bar 1 the default behavior of stems,
1691 with those on high notes pointing down and those on low notes pointing
1692 up, followed by four notes with all stems forced down, four notes with
1693 all stems forced up, and finally four notes reverted back to the
1696 @cindex Stem, example of overriding
1697 @cindex direction property, example
1699 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1701 \override Stem #'direction = #DOWN
1703 \override Stem #'direction = #UP
1705 \revert Stem #'direction
1709 Here we use the constants @code{DOWN} and @code{UP}.
1710 These have the values @code{-1} and @code{+1} respectively, and
1711 these numerical values may be used instead. The value @code{0}
1712 may also be used in some cases. It is simply treated as meaning
1713 @code{UP} for stems, but for some objects it means @q{center}.
1714 There is a constant, @code{CENTER} which has the value @code{0}.
1716 However, these explicit overrides are not usually used, as there are
1717 simpler equivalent predefined commands available. Here is a table of
1718 the commonest. The meaning of each is stated where it is not obvious.
1720 @multitable @columnfractions .2 .2 .25 .35
1725 @item @code{\arpeggioArrowDown}
1726 @tab @code{\arpeggioArrowUp}
1727 @tab @code{\arpeggioNormal}
1728 @tab Arrow is at bottom, at top, or no arrow
1729 @item @code{\dotsDown}
1731 @tab @code{\dotsNeutral}
1732 @tab Direction of movement to avoid staff lines
1733 @item @code{\dynamicDown}
1734 @tab @code{\dynamicUp}
1735 @tab @code{\dynamicNeutral}
1737 @item @code{\phrasingSlurDown}
1738 @tab @code{\phrasingSlurUp}
1739 @tab @code{\phrasingSlurNeutral}
1740 @tab Note: distinct from slur commands
1741 @item @code{\slurDown}
1743 @tab @code{\slurNeutral}
1745 @item @code{\stemDown}
1747 @tab @code{\stemNeutral}
1749 @item @code{\textSpannerDown}
1750 @tab @code{\textSpannerUp}
1751 @tab @code{\textSpannerNeutral}
1752 @tab Text entered as spanner is below/above staff
1753 @item @code{\tieDown}
1755 @tab @code{\tieNeutral}
1757 @item @code{\tupletDown}
1758 @tab @code{\tupletUp}
1759 @tab @code{\tupletNeutral}
1760 @tab Tuplets are below/above notes
1763 Note that these predefined commands may @strong{not} be
1764 preceded by @code{\once}. If you wish to limit the
1765 effect to a single note you must either use the equivalent
1766 @code{\once \override} command or use the predefined command
1767 followed after the affected note by the corresponding
1768 @code{\xxxNeutral} command.
1770 @subheading Fingering
1772 @cindex fingering, placement
1773 @cindex fingering, chords
1775 The placement of fingering on single notes can also be controlled
1776 by the @code{direction} property, but changing @code{direction}
1777 has no effect on chords. As we shall see, there are special
1778 commands which allow the fingering of individual notes
1779 of chords to be controlled, with the fingering being placed
1780 above, below, to the left or to the right of each note.
1782 First, here's the effect of @code{direction} on the fingering
1783 attached to single notes. The first bar shows the default
1784 behaviour, and the following two bars shows the effect of
1785 specifying @code{DOWN} and @code{UP}:
1787 @cindex Fingering, example of overriding
1788 @cindex direction property, example
1790 @lilypond[quote,verbatim,relative=2]
1792 \override Fingering #'direction = #DOWN
1794 \override Fingering #'direction = #UP
1798 However, overriding the @code{direction} property is not the
1799 easiest way of manually setting the fingering above or below
1800 the notes; using @code{_} or @code{^} instead of @code{-} before
1801 the fingering number is usually preferable. Here is the previous
1802 example using this method:
1804 @cindex fingering example
1806 @lilypond[quote,verbatim,relative=2]
1812 The @code{direction} property is ignored for chords, but the
1813 directional prefixes, @code{_} and @code{^} do work. By default,
1814 the fingering is automatically placed both above and below the
1815 notes of a chord, as shown:
1817 @cindex fingering example
1819 @lilypond[quote,verbatim,relative=2]
1826 but this may be overridden to manually force all or any of the
1827 individual fingering numbers above or below:
1829 @cindex fingering example
1831 @lilypond[quote,verbatim,relative=2]
1837 Even greater control over the placement of fingering of the
1838 individual notes in a chord is possible by using the
1839 @code{\set fingeringOrientations} command. The format of this
1843 @code{\set fingeringOrientations = #'([up] [left/right] [down])}
1847 @code{\set} is used because @code{fingeringOrientations} is a
1848 property of the @code{Voice} context, created and used by the
1849 @code{New_fingering_engraver}.
1851 The property may be set to a list of one to three values.
1852 It controls whether fingerings may be placed above (if
1853 @code{up} appears in the list), below (if @code{down} appears),
1854 to the left (if @code{left} appears, or to the right
1855 (if @code{right} appears). Conversely, if a location is not
1856 listed, no fingering is placed there. LilyPond takes these
1857 constraints and works out the best placement for the fingering
1858 of the notes of the following chords. Note that @code{left} and
1859 @code{right} are mutually exclusive -- fingering may be placed
1860 only on one side or the other, not both.
1862 @warning{To control the placement of the fingering of a single
1863 note using this command it is necessary to write it as a single
1864 note chord by placing angle brackets round it.}
1866 Here are a few examples:
1868 @cindex fingering example
1869 @cindex @code{\set}, example of using
1870 @cindex fingeringOrientations property, example
1872 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1873 \set fingeringOrientations = #'(left)
1875 < c-1 e-2 g-3 b-5 > 4
1876 \set fingeringOrientations = #'(left)
1878 < c-1 e-2 g-3 b-5 > 4
1879 \set fingeringOrientations = #'(up left down)
1881 < c-1 e-2 g-3 b-5 > 4
1882 \set fingeringOrientations = #'(up left)
1884 < c-1 e-2 g-3 b-5 > 4
1885 \set fingeringOrientations = #'(right)
1887 < c-1 e-2 g-3 b-5 > 4
1891 If the fingering seems a little crowded the @code{font-size}
1892 could be reduced. The default value can be seen from the
1893 @code{Fingering} object in the IR to be @code{-5}, so let's
1896 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1897 \override Fingering #'font-size = #-7
1898 \set fingeringOrientations = #'(left)
1900 < c-1 e-2 g-3 b-5 > 4
1901 \set fingeringOrientations = #'(left)
1903 < c-1 e-2 g-3 b-5 > 4
1904 \set fingeringOrientations = #'(up left down)
1906 < c-1 e-2 g-3 b-5 > 4
1907 \set fingeringOrientations = #'(up left)
1909 < c-1 e-2 g-3 b-5 > 4
1910 \set fingeringOrientations = #'(right)
1912 < c-1 e-2 g-3 b-5 > 4
1915 @node Outside-staff objects
1916 @subsection Outside-staff objects
1918 Outside-staff objects are automatically placed to avoid collisions.
1919 Objects with the lower value of the @code{outside-staff-priority}
1920 property are placed nearer to the staff, and other outside-staff
1921 objects are then raised as far as necessary to avoid collisions.
1922 The @code{outside-staff-priority} is defined in the
1923 @code{grob-interface} and so is a property of all layout objects.
1924 By default it is set to @code{#f} for all within-staff objects,
1925 and to a numerical value appropriate to each outside-staff object
1926 when the object is created. The following table shows
1927 the default numerical values for some of the commonest
1928 outside-staff objects which are, by default, placed in the
1929 @code{Staff} or @code{Voice} contexts.
1931 @multitable @columnfractions .3 .3 .3
1932 @headitem Layout Object
1934 @tab Controls position of:
1935 @item @code{MultiMeasureRestText}
1937 @tab Text over full-bar rests
1938 @item @code{TextScript}
1941 @item @code{OttavaBracket}
1943 @tab Ottava brackets
1944 @item @code{TextSpanner}
1947 @item @code{DynamicLineSpanner}
1949 @tab All dynamic markings
1950 @item @code{VoltaBracketSpanner}
1953 @item @code{TrillSpanner}
1955 @tab Spanning trills
1958 Here is an example showing the default placement of some of
1961 @cindex text spanner
1962 @cindex ottava bracket
1964 @funindex \startTextSpan
1965 @funindex startTextSpan
1966 @funindex \stopTextSpan
1967 @funindex stopTextSpan
1969 @cindex TextSpanner, example of overriding
1970 @cindex bound-details property, example
1972 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1973 % Set details for later Text Spanner
1974 \override TextSpanner #'(bound-details left text)
1975 = \markup { \small \bold Slower }
1976 % Place dynamics above staff
1978 % Start Ottava Bracket
1983 % Add Dynamic Line Spanner
1989 c\ff c \stopTextSpan
1990 % Stop Ottava Bracket
1995 This example also shows how to create Text Spanners --
1996 text with extender lines above a section of music. The
1997 spanner extends from the @code{\startTextSpan} command to
1998 the @code{\stopTextSpan} command, and the format of the
1999 text is defined by the @code{\override TextSpanner} command.
2000 For more details see @ruser{Text spanners}.
2002 It also shows how ottava brackets are created.
2004 @cindex tweaking bar number placement
2005 @cindex bar numbers, tweaking placement
2006 @cindex tweaking metronome mark placement
2007 @cindex metronome mark, tweaking placement
2008 @cindex tweaking rehearsal mark placement
2009 @cindex rehearsal marks, tweaking placement
2011 Note that bar numbers, metronome marks and rehearsal marks are not
2012 shown. By default these are created in the @code{Score} context and
2013 their @code{outside-staff-priority} is ignored relative to the layout
2014 objects which are created in the @code{Staff} context. If you wish to
2015 place bar numbers, metronome marks or rehearsal marks in accordance
2016 with the value of their @code{outside-staff-priority} the
2017 @code{Bar_number_engraver}, @code{Metronome_mark_engraver} or
2018 @code{Mark_engraver} respectively should be removed from the
2019 @code{Score} context and placed in the top @code{Staff} context. If
2020 this is done, these marks will be given the following default
2021 @code{outside-staff-priority} values:
2023 @multitable @columnfractions .3 .3
2024 @headitem Layout Object @tab Priority
2025 @item @code{RehearsalMark} @tab @code{1500}
2026 @item @code{MetronomeMark} @tab @code{1000}
2027 @item @code{BarNumber} @tab @code{ 100}
2030 If the default values of @code{outside-staff-priority} do not give you
2031 the placing you want, the priority of any of the objects may be
2032 overridden. Suppose we would like the ottava bracket to be placed
2033 below the text spanner in the example above. All we need to do is to
2034 look up the priority of @code{OttavaBracket} in the IR or in the
2035 tables above, and reduce it to a value lower than that of a
2036 @code{TextSpanner}, remembering that @code{OttavaBracket} is created
2037 in the @code{Staff} context:
2039 @cindex TextSpanner, example of overriding
2040 @cindex bound-details property, example
2042 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
2043 % Set details for later Text Spanner
2044 \override TextSpanner #'(bound-details left text)
2045 = \markup { \small \bold Slower }
2046 % Place dynamics above staff
2048 %Place following Ottava Bracket below Text Spanners
2049 \once \override Staff.OttavaBracket #'outside-staff-priority = #340
2050 % Start Ottava Bracket
2055 % Add Dynamic Line Spanner
2061 c\ff c \stopTextSpan
2062 % Stop Ottava Bracket
2067 @cindex slurs and outside-staff-priority
2068 @cindex slurs and articulations
2069 @cindex articulations and slurs
2071 Slurs by default are classed as within-staff objects, but
2072 they often appear above the staff if the notes to
2073 which they are attached are high on the staff. This can push
2074 outside-staff objects such as articulations too high, as the slur
2075 will be placed first. The @code{avoid-slur} property of the
2076 articulation can be set to @code{'inside} to bring the articulation
2077 inside the slur, but the @code{avoid-slur} property is effective
2078 only if the @code{outside-staff-priority} is also set to @code{#f}.
2079 Alternatively, the @code{outside-staff-priority} of the slur
2080 can be set to a numerical value to cause it to be placed along with
2081 other outside-staff objects according to that value. Here's an
2082 example showing the effect of the two methods:
2084 @lilypond[quote,verbatim,relative=2]
2085 c4( c^\markup\tiny\sharp d4.) c8
2087 \once \override TextScript #'avoid-slur = #'inside
2088 \once \override TextScript #'outside-staff-priority = ##f
2089 c^\markup\tiny\sharp d4.) c8
2090 \once \override Slur #'outside-staff-priority = #500
2091 c4( c^\markup\tiny\sharp d4.) c8
2094 Changing the @code{outside-staff-priority} can also be used to
2095 control the vertical placement of individual objects, although
2096 the results may not always be desirable. Suppose we would
2097 like @qq{Text3} to be placed above @qq{Text4} in the example
2098 under Automatic behavior, above (see @ref{Automatic behavior}).
2099 All we need to do is to look up the priority of @code{TextScript}
2100 in the IR or in the tables above, and increase the priority of
2101 @qq{Text3} to a higher value:
2103 @cindex TextScript, example of overriding
2104 @cindex outside-staff-priority property, example
2106 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2109 \once \override TextScript #'outside-staff-priority = #500
2114 This certainly lifts @qq{Text3} above @qq{Text4} but it also lifts it
2115 above @qq{Text2}, and @qq{Text4} now drops down. Perhaps this is not
2116 so good. What we would really like to do is to position all the
2117 annotation at the same distance above the staff. To do this, we
2118 clearly will need to space the notes out horizontally to make more
2119 room for the text. This is done using the @code{textLengthOn}
2122 @subheading \textLengthOn
2124 @cindex notes, spreading out with text
2126 @funindex \textLengthOn
2127 @funindex textLengthOn
2128 @funindex \textLengthOff
2129 @funindex textLengthOff
2131 By default, text produced by markup takes up no horizontal space
2132 as far as laying out the music is concerned. The @code{\textLengthOn}
2133 command reverses this behavior, causing the notes to be spaced
2134 out as far as is necessary to accommodate the text:
2136 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2137 \textLengthOn % Cause notes to space out to accommodate text
2144 The command to revert to the default behavior is
2145 @code{\textLengthOff}. Remember @code{\once} only works with
2146 @code{\override}, @code{\set}, @code{\revert} or @code{unset},
2147 so cannot be used with @code{\textLengthOn}.
2149 @cindex markup text, allowing collisions
2151 Markup text will also avoid notes which project above the staff.
2152 If this is not desired, the automatic displacement upwards may
2153 be turned off by setting the priority to @code{#f}. Here's an
2154 example to show how markup text interacts with such notes.
2156 @cindex TextScript, example of overriding
2157 @cindex outside-staff-priority property, example
2159 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2160 % This markup is short enough to fit without collision
2164 % This is too long to fit, so it is displaced upwards
2168 % Turn off collision avoidance
2169 \once \override TextScript #'outside-staff-priority = ##f
2173 % Turn off collision avoidance
2174 \once \override TextScript #'outside-staff-priority = ##f
2175 \textLengthOn % and turn on textLengthOn
2176 c,,2^"Long Text " % Spaces at end are honored
2181 @subheading Dynamics
2183 @cindex tweaking dynamics placement
2184 @cindex dynamics, tweaking placement
2186 Dynamic markings will normally be positioned beneath the
2187 staff, but may be positioned above with the @code{dynamicUp}
2188 command. They will be positioned vertically relative to the
2189 note to which they are attached, and will float below (or above)
2190 all within-staff objects such as phrasing slurs and bar numbers.
2191 This can give quite acceptable results, as this example
2194 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
2199 bes4.~\f\< \( bes4 bes8 des4\ff\> c16 bes\! |
2200 ees,2.~\)\mf ees4 r8 |
2203 However, if the notes and attached dynamics are close
2204 together the automatic placement will avoid collisions
2205 by displacing later dynamic markings further away, but this may
2206 not be the optimum placement, as this rather artificial example
2209 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2215 Should a similar situation arise in @q{real} music, it may be
2216 preferable to space out the notes a little further, so the dynamic
2217 markings can all fit at the same vertical distance from the staff. We
2218 were able to do this for markup text by using the @code{\textLengthOn}
2219 command, but there is no equivalent command for dynamic marks. So we
2220 shall have to work out how to do this using @code{\override} commands.
2222 @subheading Grob sizing
2225 @cindex sizing grobs
2227 First we must learn how grobs are sized. All grobs have a
2228 reference point defined within them which is used to position
2229 them relative to their parent object. This point in the grob
2230 is then positioned at a horizontal distance, @code{X-offset},
2231 and at a vertical distance, @code{Y-offset}, from its parent.
2232 The horizontal extent of the object is given by a pair of
2233 numbers, @code{X-extent}, which say where the left and right
2234 edges are relative to the reference point. The vertical extent
2235 is similarly defined by a pair of numbers, @code{Y-extent}.
2236 These are properties of all grobs which support the
2237 @code{grob-interface}.
2239 @cindex @code{extra-spacing-width}
2241 By default, outside-staff objects are given a width of zero so
2242 that they may overlap in the horizontal direction. This is done
2243 by the trick of adding infinity to the leftmost extent and
2244 minus infinity to the rightmost extent by setting the
2245 @code{extra-spacing-width} to @code{'(+inf.0 . -inf.0)}. So
2246 to ensure they do not overlap in the horizontal direction we
2247 must override this value of @code{extra-spacing-width} to
2248 @code{'(0 . 0)} so the true width shines through. This is
2249 the command to do this for dynamic text:
2252 \override DynamicText #'extra-spacing-width = #'(0 . 0)
2256 Let's see if this works in our previous example:
2258 @cindex DynamicText, example of overriding
2259 @cindex extra-spacing-width property, example
2261 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2263 \override DynamicText #'extra-spacing-width = #'(0 . 0)
2268 Well, it has certainly stopped the dynamic marks being
2269 displaced, but two problems remain. The marks should be
2270 spaced a little further apart and it would be better
2271 if they were all the same distance from the staff.
2272 We can solve the first problem easily. Instead of making
2273 the @code{extra-spacing-width} zero we could add a little
2274 more to it. The units are the space between two staff
2275 lines, so moving the left edge half a unit to the left and the
2276 right edge half a unit to the right should do it:
2278 @cindex DynamicText, example of overriding
2279 @cindex extra-spacing-width property, example
2281 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2283 % Extend width by 1 staff space
2284 \override DynamicText #'extra-spacing-width = #'(-0.5 . 0.5)
2289 This looks better, but maybe we would prefer the dynamic marks
2290 to be aligned along the same baseline rather than going up and
2291 down with the notes. The property to do this is
2292 @code{staff-padding} which is covered in the following section.
2295 @node Collisions of objects
2296 @section Collisions of objects
2300 * Fixing overlapping notation::
2301 * Real music example::
2304 @node Moving objects
2305 @subsection Moving objects
2307 @cindex moving overlapping objects
2308 @cindex moving colliding objects
2309 @cindex moving colliding grobs
2310 @cindex objects, moving colliding
2311 @cindex grobs, moving colliding
2313 This may come as a surprise, but LilyPond is not perfect. Some
2314 notation elements can overlap. This is unfortunate, but in fact
2315 rather rare. Usually the need to move objects is for clarity or
2316 aesthetic reasons -- they would look better with a little more
2317 or a little less space around them.
2319 There are three main approaches to resolving overlapping
2320 notation. They should be considered in the following order:
2324 The @strong{direction} of one of the overlapping objects may
2325 be changed using the predefined commands listed above for
2326 within-staff objects (see @ref{Within-staff objects}).
2327 Stems, slurs, beams, ties, dynamics, text and tuplets may be
2328 repositioned easily in this way. The limitation is that you
2329 have a choice of only two positions, and neither may be
2333 The @strong{object properties}, which LilyPond uses when positioning
2334 layout objects, may be modified using @code{\override}. The
2335 advantages of making changes to this type of property are (a) that
2336 some other objects will be moved automatically if necessary to make
2337 room and (b) the single override can apply to all instances of the
2338 same type of object. Such properties include:
2345 This has already been covered in some detail -- see
2346 @ref{Within-staff objects}.
2349 @code{padding}, @code{left-padding},
2350 @code{right-padding}, @code{staff-padding}
2353 @cindex left-padding property
2354 @cindex padding property
2355 @cindex right-padding property
2356 @cindex staff-padding property
2358 As an object is being positioned the value of its @code{padding}
2359 property specifies the gap that must be left between itself and the
2360 nearest edge of the object against which it is being positioned. Note
2361 that it is the @code{padding} value of the object @strong{being
2362 placed} that is used; the @code{padding} value of the object which is
2363 already placed is ignored. Gaps specified by @code{padding} can be
2364 applied to all objects which support the
2365 @code{side-position-interface}.
2367 Instead of @code{padding}, the placement of groups of accidentals
2368 is controlled by @code{left-padding} and @code{right-padding}.
2369 These properties are to be found in the @code{AccidentalPlacement}
2370 object which, note, lives in the @strong{staff} context. In the
2371 type-setting process the note heads are type-set first and then
2372 the accidentals, if any, are added to the left of the note heads
2373 using the @code{right-padding} property to determine the separation
2374 from the note heads. So only the @code{right-padding} property of the
2375 @code{AccidentalPlacement} object has any effect on the placement
2378 The @code{staff-padding} property is closely related to the
2379 @code{padding} property: @code{padding} controls the minimum amount of
2380 space between any object which supports the
2381 @code{side-position-interface} and the nearest other object (generally
2382 the note or the staff lines); @code{staff-padding} applies only to
2383 those objects which are always set outside the staff -- it controls
2384 the minimum amount of space that should be inserted between that
2385 object and the staff. Note that @code{staff-padding} has no effect on
2386 objects which are positioned relative to the note rather than the
2387 staff, even though it may be overridden without error for such objects
2388 -- it is simply ignored.
2390 To discover which padding property is required for the object you wish
2391 to reposition, you need to return to the IR and look up the object's
2392 properties. Be aware that the padding properties might not be located
2393 in the obvious object, so look in objects that appear to be related.
2395 All padding values are measured in staff spaces. For most
2396 objects, this value is set by default to be around 1.0 or less
2397 (it varies with each object). It may be overridden if a larger
2398 (or smaller) gap is required.
2401 @code{self-alignment-X}
2403 @cindex self-alignment-X property
2405 This property can be used to align the object to the left, to
2406 the right, or to center it with respect to the parent object's
2407 reference point. It may be used with all objects which support
2408 the @code{self-alignment-interface}. In general these are objects
2409 that contain text. The values are @code{LEFT}, @code{RIGHT}
2410 or @code{CENTER}. Alternatively, a numerical value between
2411 @code{-1} and @code{+1} may be specified, where @code{-1} is
2412 left-aligned, @code{+1} is right-aligned, and numbers in between
2413 move the text progressively from left-aligned to right-aligned.
2414 Numerical values greater than @code{1} may be specified to move
2415 the text even further to the left, or less than @code{-1} to
2416 move the text even further to the right. A change of @code{1}
2417 in the value corresponds to a movement of half the text's length.
2420 @code{extra-spacing-width}
2422 @cindex extra-spacing-width property
2424 This property is available for all objects which support the
2425 @code{item-interface}. It takes two numbers, the first is added
2426 to the leftmost extent and the second is added to the rightmost
2427 extent. Negative numbers move the edge to the left, positive to
2428 the right, so to widen an object the first number must be negative,
2429 the second positive. Note that not all objects honor both
2430 numbers. For example, the @code{Accidental} object only takes
2431 notice of the first (left edge) number.
2434 @code{staff-position}
2436 @cindex staff-position property
2438 @code{staff-position} is a property of the
2439 @code{staff-symbol-referencer-interface}, which is supported by
2440 objects which are positioned relative to the staff. It specifies
2441 the vertical position of the object relative to the center line
2442 of the staff in half staff-spaces. It is useful in resolving
2443 collisions between layout objects like multi-measure rests, ties
2444 and notes in different voices.
2449 @cindex force-hshift property
2451 Closely spaced notes in a chord, or notes occurring at the same
2452 time in different voices, are arranged in two, occasionally more,
2453 columns to prevent the note heads overlapping. These are called
2454 note columns, and an object called @code{NoteColumn} is created
2455 to lay out the notes in that column.
2457 The @code{force-hshift} property is a property of a @code{NoteColumn}
2458 (actually of the @code{note-column-interface}). Changing it permits a
2459 note column to be moved in units appropriate to a note column,
2460 viz. the note head width of the first voice note. It should be used
2461 in complex situations where the normal @code{\shiftOn} commands (see
2462 @ref{Explicitly instantiating voices}) do not resolve the note
2463 conflict. It is preferable to the @code{extra-offset} property for
2464 this purpose as there is no need to work out the distance in
2465 staff-spaces, and moving the notes into or out of a @code{NoteColumn}
2466 affects other actions such as merging note heads.
2471 Finally, when all else fails, objects may be manually repositioned
2472 relative to the staff center line vertically, or by displacing them by
2473 any distance to a new position. The disadvantages are that the
2474 correct values for the repositioning have to be worked out, often by
2475 trial and error, for every object individually, and, because the
2476 movement is done after LilyPond has placed all other objects, the user
2477 is responsible for avoiding any collisions that might ensue. But the
2478 main difficulty with this approach is that the repositioning values
2479 may need to be reworked if the music is later modified. The
2480 properties that can be used for this type of manual repositioning are:
2485 @cindex extra-offset property
2487 This property applies to any layout object supporting the
2488 @code{grob-interface}. It takes a pair of numbers which specify the
2489 extra displacement in the horizontal and vertical directions.
2490 Negative numbers move the object to the left or down. The units are
2491 staff-spaces. The extra displacement is made after the typesetting of
2492 objects is finished, so an object may be repositioned anywhere without
2493 affecting anything else.
2497 @cindex positions property
2499 This is most useful for manually adjusting the slope and height
2500 of beams, slurs, and tuplets. It takes a pair of numbers
2501 giving the position of the left and right ends of the beam, slur,
2502 etc. relative to the center line of the staff. Units are
2503 staff-spaces. Note, though, that slurs and phrasing slurs cannot
2504 be repositioned by arbitrarily large amounts. LilyPond first
2505 generates a list of possible positions for the slur and by default
2506 finds the slur that @qq{looks best}. If the @code{positions}
2507 property has been overridden the slur that is closest to the
2508 requested positions is selected from the list.
2513 A particular object may not have all of these properties.
2514 It is necessary to go to the IR to look up which properties
2515 are available for the object in question.
2517 Here is a list of the objects which are most likely to be
2518 involved in collisions, together with the name of the object which
2519 should be looked up in the IR in order to discover which properties
2520 should be used to move them.
2522 @multitable @columnfractions .5 .5
2523 @headitem Object type @tab Object name
2524 @item Articulations @tab @code{Script}
2525 @item Beams @tab @code{Beam}
2526 @item Dynamics (vertically) @tab @code{DynamicLineSpanner}
2527 @item Dynamics (horizontally) @tab @code{DynamicText}
2528 @item Fingerings @tab @code{Fingering}
2529 @item Rehearsal / Text marks @tab @code{RehearsalMark}
2530 @item Slurs @tab @code{Slur}
2531 @item Text e.g. @code{^"text"} @tab @code{TextScript}
2532 @item Ties @tab @code{Tie}
2533 @item Tuplets @tab @code{TupletBracket}
2537 @node Fixing overlapping notation
2538 @subsection Fixing overlapping notation
2540 Let's now see how the properties in the previous section can
2541 help to resolve overlapping notation.
2543 @subheading padding property
2546 @cindex fixing overlapping notation
2547 @cindex overlapping notation
2549 The @code{padding} property can be set to increase
2550 (or decrease) the distance between symbols that are printed
2551 above or below notes.
2553 @cindex Script, example of overriding
2554 @cindex padding property, example
2556 @lilypond[quote,fragment,relative=1,verbatim]
2558 \override Script #'padding = #3
2562 @cindex MetronomeMark, example of overriding
2563 @cindex padding property, example
2565 @lilypond[quote,fragment,relative=1,verbatim]
2566 % This will not work, see below:
2567 \override MetronomeMark #'padding = #3
2571 \override Score.MetronomeMark #'padding = #3
2576 Note in the second example how important it is to figure out what
2577 context handles a certain object. Since the @code{MetronomeMark}
2578 object is handled in the @code{Score} context, property changes in the
2579 @code{Voice} context will not be noticed. For more details, see
2580 @ruser{Modifying properties}.
2582 If the @code{padding} property of an object is increased when that
2583 object is in a stack of objects being positioned according to
2584 their @code{outside-staff-priority}, then that object and all
2585 objects outside it are moved.
2588 @subheading left-padding and right-padding
2590 @cindex left-padding property
2591 @cindex right-padding property
2593 The @code{right-padding} property affects the spacing between the
2594 accidental and the note to which it applies. It is not often
2595 required, but the following example shows one situation where it
2596 is needed. Suppose we wish to show a chord containing both
2597 a B-natural and a B-flat. To avoid ambiguity we would like to
2598 precede the notes with both a natural and a flat sign. Here
2599 are a few attempts to do this:
2601 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2607 None work, with the second two showing bad collisions between
2610 One way of achieving this is to override the accidental stencil
2611 with a markup containing the natural and flat symbols in the
2612 order we would like, like this:
2614 @cindex Accidental, example of overriding
2615 @cindex text property, example
2616 @cindex stencil property, example
2617 @cindex AccidentalPlacement, example of overriding
2618 @cindex right-padding property, example
2620 @lilypond[quote,ragged-right,verbatim]
2621 naturalplusflat = \markup { \natural \flat }
2623 \once \override Accidental
2624 #'stencil = #ly:text-interface::print
2625 \once \override Accidental #'text = #naturalplusflat
2626 \once \override Score.AccidentalPlacement #'right-padding = #1.5
2632 This necessarily uses an override for the accidental stencil which
2633 will not be covered until later. The stencil type must be a
2634 procedure, here changed to print the contents of the @code{text}
2635 property of @code{Accidental}, which itself is set to be a natural
2636 sign followed by a flat sign. These are then moved further away
2637 from the note head by overriding @code{right-padding}.
2641 @subheading staff-padding property
2643 @cindex aligning objects on a baseline
2644 @cindex objects, aligning on a baseline
2646 @code{staff-padding} can be used to align objects such as dynamics
2647 along a baseline at a fixed height above the staff, rather than at a
2648 height dependent on the position of the note to which they are
2649 attached. It is not a property of @code{DynamicText} but of
2650 @code{DynamicLineSpanner}. This is because the baseline should apply
2651 equally to @strong{all} dynamics, including those created as extended
2652 spanners. So this is the way to align the dynamic marks in the
2653 example taken from the previous section:
2655 @cindex DynamicText, example of overriding
2656 @cindex extra-spacing-width property, example
2657 @cindex DynamicLineSpanner, example of overriding
2658 @cindex staff-padding property, example
2660 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2662 % Extend width by 1 unit
2663 \override DynamicText #'extra-spacing-width = #'(-0.5 . 0.5)
2664 % Align dynamics to a base line 2 units above staff
2665 \override DynamicLineSpanner #'staff-padding = #2
2670 @subheading self-alignment-X property
2672 The following example shows how this can resolve the collision
2673 of a string fingering object with a note's stem by aligning the
2674 right edge with the reference point of the parent note:
2676 @cindex StringNumber, example of overriding
2677 @cindex self-alignment-X property, example
2679 @lilypond[quote,fragment,ragged-right,verbatim,relative=3]
2682 \once \override StringNumber #'self-alignment-X = #RIGHT
2686 @subheading staff-position property
2688 @cindex object collision within a staff
2690 Multimeasure rests in one voice can collide with notes in another.
2691 Since these rests are typeset centered between the bar lines, it
2692 would require significant effort for LilyPond to figure out which
2693 other notes might collide with it, since all the current collision
2694 handling between notes and between notes and rests is done only
2695 for notes and rests that occur at the same time. Here's an
2696 example of a collision of this type:
2698 @lilypond[quote,verbatim,fragment,ragged-right, relative=1]
2699 << {c c c c} \\ {R1} >>
2702 The best solution here is to move the multimeasure rest down, since
2703 the rest is in voice two. The default in @code{\voiceTwo} (i.e. in
2704 the second voice of a @code{<<@{...@} \\ @{...@}>>} construct) is that
2705 @code{staff-position} is set to -4 for MultiMeasureRest, so we need to
2706 move it, say, four half-staff spaces down to @code{-8}.
2708 @cindex MultiMeasureRest, example of overriding
2709 @cindex staff-position property, example
2711 @lilypond[quote,verbatim,fragment,ragged-right, relative=1]
2715 \override MultiMeasureRest #'staff-position = #-8
2720 This is better than using, for example, @code{extra-offset},
2721 because the ledger line above the rest is inserted automatically.
2723 @subheading extra-offset property
2725 @cindex positioning objects
2726 @cindex positioning grobs
2727 @cindex objects, positioning
2728 @cindex grobs, positioning
2730 The @code{extra-offset} property provides complete control over the
2731 positioning of an object both horizontally and vertically.
2733 In the following example, the second fingering is moved a little to
2734 the left, and 1.8 staff space downwards:
2736 @cindex Fingering, example of overriding
2737 @cindex extra-offset property, example
2739 @lilypond[quote,fragment,relative=1,verbatim]
2742 \once \override Fingering
2743 #'extra-offset = #'(-0.3 . -1.8)
2748 @subheading positions property
2750 @cindex controlling tuplets, slurs, phrasing slurs, and beams manually
2751 @cindex manually controlling tuplets, slurs, phrasing slurs, and beams
2752 @cindex tuplet beams, controlling manually
2753 @cindex slurs, controlling manually
2754 @cindex phrasing slurs, controlling manually
2755 @cindex beams, controlling manually
2757 The @code{positions} property allows the position and slope of
2758 tuplets, slurs, phrasing slurs and beams to be controlled manually.
2759 Here's an example which has an ugly phrasing slur due to its trying to
2760 avoid the slur on the acciaccatura.
2762 @lilypond[quote,verbatim,fragment,ragged-right,relative=1]
2763 r4 \acciaccatura e8\( d8 c ~c d c d\)
2767 We could simply move the phrasing slur above the notes, and this
2768 would be the preferred solution:
2770 @lilypond[quote,verbatim,fragment,ragged-right,relative=1]
2773 \acciaccatura e8\( d8 c ~c d c d\)
2777 But if there were some reason why this could not be done the
2778 other alternative would be to move the left end of the phrasing
2779 slur down a little using the @code{positions} property. This
2780 also resolves the rather nasty shape.
2782 @cindex PhrasingSlur, example of overriding
2783 @cindex positions property, example
2785 @lilypond[quote,verbatim,fragment,ragged-right,relative=1]
2787 \once \override PhrasingSlur #'positions = #'(-4 . -3)
2789 e8\( d8 c ~c d c d\)
2792 Here's a further example taken from the opening of the left-hand
2793 staff of Chopin's Prelude Op 28 No. 2. We see that the beam
2794 collides with the upper notes:
2796 @lilypond[quote,verbatim,fragment,ragged-right]
2799 << {b,8 ais, b, g,} \\ {e, g e, g} >>
2800 << {b,8 ais, b, g,} \\ {e, g e, g} >>
2805 This can be resolved by manually moving both ends of the beam
2806 up from their position at 2 staff-spaces above the center line to,
2809 @cindex Beam, example of overriding
2810 @cindex positions property, example
2812 @lilypond[quote,verbatim,fragment,ragged-right]
2816 \override Beam #'positions = #'(3 . 3)
2821 << {b,8 ais, b, g,} \\ {e, g e, g} >>
2826 Note that the override continues to apply in the first voice of
2827 the second block of quavers, but not to any of the beams in the
2830 @subheading force-hshift property
2832 @c FIXME: formatting stuff (ie not important right now IMO)
2833 @c @a nchor Chopin finally corrected TODOgp
2835 We can now see how to apply the final corrections to the Chopin
2836 example introduced at the end of @ref{I'm hearing Voices}, which
2837 was left looking like this:
2839 @lilypond[quote,verbatim,fragment,ragged-right]
2840 \new Staff \relative c'' {
2843 { c2 aes4. bes8 } \\
2855 The lower two notes of the first chord (i.e, those in the third voice)
2856 should not be shifted away from the note column of the higher two
2857 notes. To correct this we set @code{force-hshift}, which is a
2858 property of @code{NoteColumn}, of these notes to zero. The lower note
2859 of the second chord is best placed just to the right of the higher
2860 notes. We achieve this by setting @code{force-hshift} of this note to
2861 0.5, ie half a note head's width to the right of the note column of
2864 Here's the final result:
2866 @cindex NoteColumn, example of overriding
2867 @cindex force-hshift property, example
2869 @lilypond[quote,verbatim,fragment,ragged-right]
2870 \new Staff \relative c'' {
2873 { c2 aes4. bes8 } \\
2876 \once \override NoteColumn #'force-hshift = #0 <ees c>2
2877 \once \override NoteColumn #'force-hshift = #0.5 des2
2885 @node Real music example
2886 @subsection Real music example
2888 We end this section on Tweaks by showing the steps to be taken to
2889 deal with a tricky example which needs several tweaks to produce
2890 the desired output. The example has been deliberately chosen to
2891 illustrate the use of the Notation Reference to resolve unusual
2892 problems with notation. It is not representative of more usual
2893 engraving process, so please do not let these difficulties put
2894 you off! Fortunately, difficulties like these are not very common!
2896 The example is from Chopin's Première Ballade, Op. 23, bars 6 to
2897 9, the transition from the opening Lento to Moderato.
2898 Here, first, is what we want the output to look like, but to avoid
2899 over-complicating the example too much we have left out the
2900 dynamics, fingering and pedalling.
2902 @c The following should appear as music without code
2903 @c This example should not be indexed
2904 @lilypond[quote,ragged-right]
2905 rhMusic = \relative c'' {
2908 \once \override Tie #'staff-position = #3.5
2912 \mergeDifferentlyHeadedOn
2913 \mergeDifferentlyDottedOn
2914 bes2.^\markup {\bold "Moderato"} r8
2916 {c,8[ d fis bes a] | }
2918 % Reposition the c2 to the right of the merged note
2919 {c,8~ \once \override NoteColumn #'force-hshift = #1.0
2920 % Move the c2 out of the main note column so the merge will work
2923 % Stem on the d2 must be down to permit merging
2924 {s8 \stemDown \once \override Stem #'transparent = ##t d2}
2928 \mergeDifferentlyHeadedOff
2929 \mergeDifferentlyDottedOff
2933 lhMusic = \relative c' {
2935 <d g, d>1)\arpeggio |
2942 \new Staff = "RH" <<
2946 \new Staff = "LH" <<
2955 We note first that the right hand part in the third bar
2956 requires four voices. These are the five beamed eighth notes,
2957 the tied C, the half-note D which is merged with the eighth note
2958 D, and the dotted quarter note F-sharp, which is also merged with
2959 the eighth note at the same pitch. Everything else is in a single
2960 voice, so the easiest way is to introduce these four voices
2961 temporarily at the time they are needed. If you have forgotten
2962 how to do this, look at @ref{I'm hearing Voices}. Let us begin
2963 by entering the notes as two variables and setting up the staff
2964 structure in a score block, and see what LilyPond produces by
2967 @lilypond[quote,verbatim,ragged-right]
2968 rhMusic = \relative c'' {
2973 % Start polyphonic section of four voices
2975 {c,8 d fis bes a | }
2986 lhMusic = \relative c' {
2995 \new Staff = "RH" <<
2999 \new Staff = "LH" <<
3008 All the notes are right, but the appearance is far from satisfactory.
3009 The tie clashes with the change in time signature, the beaming in the
3010 third bar is wrong, the notes are not merged together, and several
3011 notation elements are missing. Let's first deal with the easier
3012 things. We can correct the beaming by inserting a beam manually, and
3013 we can easily add the left hand slur and the right hand phrasing slur,
3014 since these were all covered in the Tutorial. Doing this gives:
3016 @lilypond[quote,verbatim,ragged-right]
3017 rhMusic = \relative c'' {
3022 % Start polyphonic section of four voices
3024 {c,8[ d fis bes a] | }
3035 lhMusic = \relative c' {
3044 \new Staff = "RH" <<
3048 \new Staff = "LH" <<
3057 The first bar is now correct. The second bar contains an arpeggio and
3058 is terminated by a double bar line. How do we do these, as they have
3059 not been mentioned in this Learning Manual? This is where we need to
3060 turn to the Notation Reference. Looking up @q{arpeggio} and @q{bar
3061 line} in the index quickly shows us that an arpeggio is produced by
3062 appending @code{\arpeggio} to a chord, and a double bar line is
3063 produced by the @code{\bar "||"} command. That's easily done. We
3064 next need to correct the collision of the tie with the time signature.
3065 This is best done by moving the tie upwards. Moving objects was
3066 covered earlier in @ref{Moving objects}, which says that objects
3067 positioned relative to the staff can be moved by overriding their
3068 @code{staff-position} property, which is specified in half staff
3069 spaces relative to the center line of the staff. So the following
3070 override placed just before the first tied note would move the tie up
3071 to 3.5 half staff spaces above the center line:
3073 @code{\once \override Tie #'staff-position = #3.5}
3075 This completes bar two, giving:
3077 @lilypond[quote,verbatim,ragged-right]
3078 rhMusic = \relative c'' {
3080 \once \override Tie #'staff-position = #3.5
3085 % Start polyphonic section of four voices
3087 {c,8[ d fis bes a] | }
3098 lhMusic = \relative c' {
3100 <d g, d>1)\arpeggio |
3107 \new Staff = "RH" <<
3111 \new Staff = "LH" <<
3120 On to bar three and the start of the Moderato section. The tutorial
3121 showed how to add embolded text with the @code{\markup} command, so
3122 adding @q{Moderato} in bold is easy. But how do we merge notes in
3123 different voices together? This is where we need to turn to the
3124 Notation Reference for help. A search for @qq{merge} in the Notation
3125 Reference index quickly leads us to the commands for merging
3126 differently headed and differently dotted notes in @ruser{Collision
3127 resolution}. In our example we need to merge both types of note for
3128 the duration of the polyphonic section in bar 3, so using the
3129 information we find in the Notation Reference we add
3132 \mergeDifferentlyHeadedOn
3133 \mergeDifferentlyDottedOn
3137 to the start of that section and
3140 \mergeDifferentlyHeadedOff
3141 \mergeDifferentlyDottedOff
3147 @lilypond[quote,verbatim,ragged-right]
3148 rhMusic = \relative c'' {
3150 \once \override Tie #'staff-position = #3.5
3154 bes2.^\markup {\bold "Moderato"} r8
3155 \mergeDifferentlyHeadedOn
3156 \mergeDifferentlyDottedOn
3157 % Start polyphonic section of four voices
3159 {c,8[ d fis bes a] | }
3167 \mergeDifferentlyHeadedOff
3168 \mergeDifferentlyDottedOff
3172 lhMusic = \relative c' {
3174 <d g, d>1)\arpeggio |
3181 \new Staff = "RH" <<
3185 \new Staff = "LH" <<
3194 These overrides have merged the two F-sharp notes, but not the two
3195 on D. Why not? The answer is there in the same section in the
3196 Notation Reference -- notes being merged must have stems in
3197 opposite directions and two notes cannot be merged successfully if
3198 there is a third note in the same note column. Here the two D's
3199 both have upward stems and there is a third note -- the C. We know
3200 how to change the stem direction using @code{\stemDown}, and
3201 the Notation Reference also says how to move the C -- apply a shift
3202 using one of the @code{\shift} commands. But which one?
3203 The C is in voice two which has shift off, and the two D's are in
3204 voices one and three, which have shift off and shift on,
3205 respectively. So we have to shift the C a further level still
3206 using @code{\shiftOnn} to avoid it interfering with the two D's.
3207 Applying these changes gives:
3209 @cindex Tie, example of overriding
3210 @cindex staff-position property, example
3212 @lilypond[quote,verbatim,ragged-right]
3213 rhMusic = \relative c'' {
3215 \once \override Tie #'staff-position = #3.5
3219 bes2.^\markup {\bold "Moderato"} r8
3220 \mergeDifferentlyHeadedOn
3221 \mergeDifferentlyDottedOn
3222 % Start polyphonic section of four voices
3224 {c,8[ d fis bes a] | }
3226 % Move the c2 out of the main note column so the merge will work
3227 {c,8~ \shiftOnn c2 | }
3229 % Stem on the d2 must be down to permit merging
3230 {s8 \stemDown d2 | }
3234 \mergeDifferentlyHeadedOff
3235 \mergeDifferentlyDottedOff
3239 lhMusic = \relative c' {
3241 <d g, d>1)\arpeggio |
3248 \new Staff = "RH" <<
3252 \new Staff = "LH" <<
3261 Nearly there. Only two problems remain: The downward stem on the
3262 merged D should not be there, and the C would be better positioned
3263 to the right of the D's. We know how to do both of these from the
3264 earlier tweaks: we make the stem transparent, and move the C with
3265 the @code{force-hshift} property. Here's the final result:
3267 @cindex NoteColumn, example of overriding
3268 @cindex force-hshift property, example
3269 @cindex Stem, example of overriding
3270 @cindex transparent property, example
3272 @lilypond[quote,verbatim,ragged-right]
3273 rhMusic = \relative c'' {
3276 \once \override Tie #'staff-position = #3.5
3280 bes2.^\markup {\bold "Moderato"} r8
3281 \mergeDifferentlyHeadedOn
3282 \mergeDifferentlyDottedOn
3284 {c,8[ d fis bes a] | }
3286 % Reposition the c2 to the right of the merged note
3287 {c,8~ \once \override NoteColumn #'force-hshift = #1.0
3288 % Move the c2 out of the main note column so the merge will work
3291 % Stem on the d2 must be down to permit merging
3292 {s8 \stemDown \once \override Stem #'transparent = ##t d2}
3296 \mergeDifferentlyHeadedOff
3297 \mergeDifferentlyDottedOff
3301 lhMusic = \relative c' {
3303 <d g, d>1)\arpeggio |
3310 \new Staff = "RH" <<
3314 \new Staff = "LH" <<
3324 @node Further tweaking
3325 @section Further tweaking
3328 * Other uses for tweaks::
3329 * Using variables for tweaks::
3330 * Other sources of information::
3331 * Avoiding tweaks with slower processing::
3332 * Advanced tweaks with Scheme::
3335 @node Other uses for tweaks
3336 @subsection Other uses for tweaks
3338 @cindex transparent property, use of
3339 @cindex objects, making invisible
3340 @cindex removing objects
3341 @cindex objects, removing
3342 @cindex hiding objects
3343 @cindex objects, hiding
3344 @cindex invisible objects
3345 @cindex objects, invisible
3346 @cindex tying notes across voices
3348 @subheading Tying notes across voices
3350 The following example demonstrates how to connect notes in
3351 different voices using ties. Normally, only two notes in the
3352 same voice can be connected with ties. By using two voices,
3353 with the tied notes in one of them
3355 @lilypond[quote,fragment,relative=2]
3356 << { b8~ b8\noBeam }
3362 and blanking the first up-stem in that voice, the tie appears to
3365 @cindex Stem, example of overriding
3366 @cindex transparent property, example
3368 @lilypond[quote,fragment,relative=2,verbatim]
3371 \once \override Stem #'transparent = ##t
3379 To make sure that the just-blanked stem doesn't squeeze the tie
3380 too much, we can lengthen the stem by setting the
3381 @code{length} to @code{8},
3383 @lilypond[quote,fragment,relative=2,verbatim]
3386 \once \override Stem #'transparent = ##t
3387 \once \override Stem #'length = #8
3395 @subheading Simulating a fermata in MIDI
3397 @cindex stencil property, use of
3398 @cindex fermata, implementing in MIDI
3400 For outside-staff objects it is usually better to override the
3401 object's @code{stencil} property rather than its @code{transparent}
3402 property when you wish to remove it from the printed output.
3403 Setting the @code{stencil} property of an object to @code{#f} will
3404 remove that object entirely from the printed output. This means it
3405 has no effect on the placement of other objects placed relative to
3408 For example, if we wished to change the metronome setting in order
3409 to simulate a fermata in the MIDI output we would not want the
3410 metronome markings to appear in the printed output, and we would
3411 not want it to influence the spacing between the two systems or
3412 the positions of adjacent annotations on the staff. So setting
3413 its @code{stencil} property to @code{#f} would be the best way.
3414 We show here the effect of the two methods:
3416 @cindex MetronomeMark, example of overriding
3417 @cindex transparent property, example
3419 @lilypond[quote,verbatim,ragged-right]
3422 % Visible tempo marking
3425 \once \override Score.MetronomeMark #'transparent = ##t
3426 % Invisible tempo marking to lengthen fermata in MIDI
3429 % New tempo for next section
3438 @cindex MetronomeMark, example of overriding
3439 @cindex stencil property, example
3441 @lilypond[quote,verbatim,ragged-right]
3444 % Visible tempo marking
3447 \once \override Score.MetronomeMark #'stencil = ##f
3448 % Invisible tempo marking to lengthen fermata in MIDI
3451 % New tempo for next section
3461 Both methods remove the metronome mark which lengthens the fermata
3462 from the printed output, and both affect the MIDI timing as
3463 required, but the transparent metronome mark in the first line
3464 forces the following tempo indication too high while the
3465 second (with the stencil removed) does not.
3467 @node Using variables for tweaks
3468 @subsection Using variables for tweaks
3470 @cindex variables, using for tweaks
3471 @cindex using variables for tweaks
3472 @cindex tweaks, using variables for
3474 Override commands are often long and tedious to type, and they
3475 have to be absolutely correct. If the same overrides are to be
3476 used many times it may be worth defining variables to hold them.
3478 Suppose we wish to emphasize certain words in lyrics by printing
3479 them in bold italics. The @code{\italic} and @code{\bold}
3480 commands only work within lyrics if they are embedded, together with
3481 the word or words to be modified, within a @code{\markup} block,
3482 which makes them tedious to enter. The need to embed the words
3483 themselves prevents their use in simple variables. As an
3484 alternative can we use @code{\override} and @code{\revert} commands?
3487 @code{\override Lyrics . LyricText #'font-shape = #'italic}
3488 @code{\override Lyrics . LyricText #'font-series = #'bold}
3490 @code{\revert Lyrics . LyricText #'font-shape}
3491 @code{\revert Lyrics . LyricText #'font-series}
3494 These would also be extremely tedious to enter if there were many
3495 words requiring emphasis. But we @emph{can} define these as two
3496 variables and use those to bracket the words to be emphasized.
3497 Another advantage of using variables for these overrides is that
3498 the spaces around the dot are not necessary, since they are not
3499 being interpreted in @code{\lyricmode} directly. Here's an example
3500 of this, although in practice we would choose shorter names
3501 for the variables to make them quicker to type:
3503 @cindex LyricText, example of overriding
3504 @cindex font-shape property, example
3505 @cindex font-series property, example
3507 @lilypond[quote,verbatim]
3509 \override Lyrics.LyricText #'font-shape = #'italic
3510 \override Lyrics.LyricText #'font-series = #'bold
3513 \revert Lyrics.LyricText #'font-shape
3514 \revert Lyrics.LyricText #'font-series
3517 global = { \time 4/4 \partial 4 \key c \major}
3518 SopranoMusic = \relative c' { c4 | e4. e8 g4 g | a a g }
3519 AltoMusic = \relative c' { c4 | c4. c8 e4 e | f f e }
3520 TenorMusic = \relative c { e4 | g4. g8 c4. b8 | a8 b c d e4 }
3521 BassMusic = \relative c { c4 | c4. c8 c4 c | f8 g a b c4 }
3522 VerseOne = \lyrics { E -- | ter -- nal \emphasize Fa -- ther, \normal | strong to save, }
3523 VerseTwo = \lyricmode { O | \emphasize Christ, \normal whose voice the | wa -- ters heard, }
3524 VerseThree = \lyricmode { O | \emphasize Ho -- ly Spi -- rit, \normal | who didst brood }
3525 VerseFour = \lyricmode { O | \emphasize Tri -- ni -- ty \normal of | love and pow'r }
3531 \new Voice = "Soprano" { \voiceOne \global \SopranoMusic }
3532 \new Voice = "Alto" { \voiceTwo \AltoMusic }
3533 \new Lyrics \lyricsto "Soprano" { \VerseOne }
3534 \new Lyrics \lyricsto "Soprano" { \VerseTwo }
3535 \new Lyrics \lyricsto "Soprano" { \VerseThree }
3536 \new Lyrics \lyricsto "Soprano" { \VerseFour }
3540 \new Voice = "Tenor" { \voiceOne \TenorMusic }
3541 \new Voice = "Bass" { \voiceTwo \BassMusic }
3549 @node Other sources of information
3550 @subsection Other sources of information
3552 The Internals Reference documentation contains a lot of information
3553 about LilyPond, but even more information can be gathered by
3554 looking at the internal LilyPond files. To explore these, you must
3555 first find the directory appropriate to your system. The location
3556 of this directory depends (a) on whether you obtained LilyPond
3557 by downloading a precompiled binary from lilypond.org
3558 or whether you installed it from a package manager (i.e.
3559 distributed with Linux, or installed under fink or cygwin) or
3560 compiled it from source, and (b) on which operating system it is
3563 @strong{Downloaded from lilypond.org}
3569 @file{@var{INSTALLDIR}/lilypond/usr/share/lilypond/current/}
3574 @file{@var{INSTALLDIR}/LilyPond.app/Contents/Resources/share/lilypond/current/}
3575 by either @code{cd}-ing into this directory from the
3576 Terminal, or control-clicking on the LilyPond application and
3577 selecting @q{Show Package Contents}.
3581 Using Windows Explorer, navigate to
3582 @file{@var{INSTALLDIR}/LilyPond/usr/share/lilypond/current/}
3586 @strong{Installed from a package manager or compiled from source}
3589 @file{@var{PREFIX}/share/lilypond/@var{X.Y.Z}/}, where
3590 @var{PREFIX} is set by your package manager or @code{configure}
3591 script, and @var{X.Y.Z} is the LilyPond version number.
3595 Within this directory the two interesting subdirectories are
3598 @item @file{ly/} - contains files in LilyPond format
3599 @item @file{scm/} - contains files in Scheme format
3602 Let's begin by looking at some files in @file{ly/}.
3603 Open @file{ly/property-init.ly} in a text editor. The one
3604 you normally use for @code{.ly} files will be fine. This file
3605 contains the definitions of all the standard LilyPond predefined
3606 commands, such as @code{\stemUp} and @code{\slurDotted}. You will
3607 see that these are nothing more than definitions of variables
3608 containing one or a group of @code{\override} commands. For
3609 example, @code{/tieDotted} is defined to be:
3613 \override Tie #'dash-period = #0.75
3614 \override Tie #'dash-fraction = #0.1
3618 If you do not like the default values these predefined commands can
3619 be redefined easily, just like any other variable, at the
3620 head of your input file.
3622 The following are the most useful files to be found in
3625 @multitable @columnfractions .4 .6
3628 @item @file{ly/engraver-init.ly}
3629 @tab Definitions of engraver Contexts
3630 @item @file{ly/paper-defaults-init.ly}
3631 @tab Specifications of paper-related defaults
3632 @item @file{ly/performer-init.ly}
3633 @tab Definitions of performer Contexts
3634 @item @file{ly/property-init.ly}
3635 @tab Definitions of all common predefined commands
3636 @item @file{ly/spanner-init.ly}
3637 @tab Definitions of spanner-related predefined commands
3640 Other settings (such as the definitions of markup commands) are
3641 stored as @code{.scm} (Scheme) files. The Scheme programming
3642 language is used to provide a programmable interface into
3643 LilyPond internal operation. Further explanation of these files
3644 is currently outside the scope of this manual, as a knowledge of
3645 the Scheme language is required. Users should be warned that
3646 a substantial amount of technical knowledge or time is required
3647 to understand Scheme and these files (see @ref{Scheme tutorial}).
3649 If you have this knowledge, the Scheme files which may be of
3652 @multitable @columnfractions .4 .6
3655 @item @file{scm/auto-beam.scm}
3656 @tab Sub-beaming defaults
3657 @item @file{scm/define-grobs.scm}
3658 @tab Default settings for grob properties
3659 @item @file{scm/define-markup-commands.scm}
3660 @tab Specify all markup commands
3661 @item @file{scm/midi.scm}
3662 @tab Default settings for MIDI output
3663 @item @file{scm/output-lib.scm}
3664 @tab Settings that affect appearance of frets, colors,
3665 accidentals, bar lines, etc
3666 @item @file{scm/parser-clef.scm}
3667 @tab Definitions of supported clefs
3668 @item @file{scm/script.scm}
3669 @tab Default settings for articulations
3674 @node Avoiding tweaks with slower processing
3675 @subsection Avoiding tweaks with slower processing
3677 LilyPond can perform extra checks while it processes input files. These
3678 checks will take extra time to perform, but fewer manual tweaks
3679 may be required to obtain an acceptable result. If a text script
3680 or part of the lyrics extends over the margins these checks will
3681 compress that line of the score just enough to fit within the
3684 To be effective under all circumstances these checks must be enabled
3685 by placing the overrides in a Score @code{\with} block, rather than
3686 in-line in music, as follows:
3690 % Makes sure text scripts and lyrics are within the paper margins
3691 \override PaperColumn #'keep-inside-line = ##t
3692 \override NonMusicalPaperColumn #'keep-inside-line = ##t
3698 @node Advanced tweaks with Scheme
3699 @subsection Advanced tweaks with Scheme
3701 Although many things are possible with the @code{\override} and
3702 @code{\tweak} commands, an even more powerful way of modifying
3703 the action of LilyPond is available through a programmable
3704 interface to the LilyPond internal operation. Code written in
3705 the Scheme programming language can be incorporated directly in
3706 the internal operation of LilyPond. Of course, at least a basic
3707 knowledge of programming in Scheme is required to do this, and an
3708 introduction is provided in the @ref{Scheme tutorial}.
3710 As an illustration of one of the many possibilities, instead of
3711 setting a property to a constant it can be set to a Scheme
3712 procedure which is then called whenever that property is accessed
3713 by LilyPond. The property can then be set dynamically to a value
3714 determined by the procedure at the time it is called. In this
3715 example we color the note head in accordance with its position on
3718 @cindex x11-color function, example of using
3719 @cindex NoteHead, example of overriding
3720 @cindex color property, setting to Scheme procedure
3722 @lilypond[quote,verbatim,ragged-right]
3723 #(define (color-notehead grob)
3724 "Color the notehead according to its position on the staff."
3725 (let ((mod-position (modulo (ly:grob-property grob 'staff-position) 7)))
3727 ;; Return rainbow colors
3728 ((1) (x11-color 'red )) ; for C
3729 ((2) (x11-color 'orange )) ; for D
3730 ((3) (x11-color 'yellow )) ; for E
3731 ((4) (x11-color 'green )) ; for F
3732 ((5) (x11-color 'blue )) ; for G
3733 ((6) (x11-color 'purple )) ; for A
3734 ((0) (x11-color 'violet )) ; for B
3740 % Arrange to obtain color from color-notehead procedure
3741 \override NoteHead #'color = #color-notehead
3748 Some -- where o -- ver the Rain -- bow, way up high,
3752 Further examples showing the use of these programmable interfaces
3753 can be found in @ref{Tweaking with Scheme}.