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2 @c This file is part of lilypond-learning.tely
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11 @chapter Tweaking output
13 This chapter discusses how to modify output. LilyPond is extremely
14 configurable; virtually every fragment of output may be changed.
19 * The Internals Reference manual::
20 * Appearance of objects::
21 * Placement of objects::
22 * Collisions of objects::
27 @section Tweaking basics
30 * Introduction to tweaks::
31 * Objects and interfaces::
32 * Naming conventions of objects and properties::
36 @node Introduction to tweaks
37 @subsection Introduction to tweaks
39 @q{Tweaking} is a LilyPond term for the various methods available
40 to the user for modifying the actions taken during interpretation
41 of the input file and modifying the appearance of the printed
42 output. Some tweaks are very easy to use; others are more
43 complex. But taken together the methods available for tweaking
44 permit almost any desired appearance of the printed music to be
47 In this section we cover the basic concepts required to understand
48 tweaking. Later we give a variety of ready-made commands which can
49 simply be copied to obtain the same effect in your own scores, and
50 at the same time we show how these commands may be constructed so
51 that you may learn how to develop your own tweaks.
53 Before starting on this Chapter you may wish to review the section
54 @ref{Contexts and engravers}, as Contexts, Engravers, and the
55 Properties contained within them are fundamental to understanding
56 and constructing Tweaks.
58 @node Objects and interfaces
59 @subsection Objects and interfaces
66 Tweaking involves modifying the internal operation and structures
67 of the LilyPond program, so we must first introduce some terms
68 which are used to describe those internal operations and
71 The term @q{Object} is a generic term used to refer to the
72 multitude of internal structures built by LilyPond during the
73 processing of an input file. So when a command like @code{\new
74 Staff} is encountered a new object of type @code{Staff} is
75 constructed. That @code{Staff} object then holds all the
76 properties associated with that particular staff, for example, its
77 name and its key signature, together with details of the engravers
78 which have been assigned to operate within that staff's context.
79 Similarly, there are objects to hold the properties of all other
80 contexts, such as @code{Voice} objects, @code{Score} objects,
81 @code{Lyrics} objects, as well as objects to represent all
82 notational elements such as bar lines,
83 note heads, ties, dynamics, etc. Every object has its own set of
86 Some types of object are given special names. Objects which
87 represent items of notation on the printed output such as
88 note heads, stems, slurs, ties, fingering, clefs, etc are called
89 @q{Layout objects}, often known as @q{Graphical Objects}, or
90 @q{Grobs} for short. These are still objects in the generic sense
91 above, and so they too all have properties associated with them,
92 such as their position, size, color, etc.
94 Some layout objects are still more specialised. Phrasing slurs,
95 crescendo hairpins, ottavo marks, and many other grobs are not
96 localised in a single place -- they have a starting point, an
97 ending point, and maybe other properties concerned with their
98 shape. Objects with an extended shape like these are called
101 It remains to explain what @q{Interfaces} are. Many objects,
102 even though they are quite different, share common features
103 which need to be processed in the same way.
104 For example, all grobs have a color, a size, a position, etc,
105 and all these properties are processed in the same way during
107 interpretation of the input file. To simplify these internal
108 operations these common actions and properties are grouped
109 together in an object called a @code{grob-interface}. There
110 are many other groupings of common properties like this, each
111 one given a name ending in @code{interface}. In total there
112 are over 100 such interfaces. We shall see later why this is
113 of interest and use to the user.
115 These, then, are the main terms relating to objects which we
116 shall use in this chapter.
118 @node Naming conventions of objects and properties
119 @subsection Naming conventions of objects and properties
121 We met some object naming conventions previously, in
122 @ref{Contexts and engravers}. Here for reference is a list
123 of the most common object and property types together with
124 the conventions for naming them and a couple of examples of
125 some real names. We have used A to stand for any capitalised
126 alphabetic character and aaa to stand for any number of
127 lower-case alphabetic characters. Other characters are used
130 @multitable @columnfractions .33 .33 .33
131 @headitem Object/property type
132 @tab Naming convention
135 @tab Aaaa or AaaaAaaaAaaa
136 @tab Staff, GrandStaff
138 @tab Aaaa or AaaaAaaaAaaa
141 @tab Aaaa_aaa_engraver
142 @tab Clef_engraver, Note_heads_engraver
144 @tab aaa-aaa-interface
145 @tab grob-interface, break-aligned-interface
146 @item Context Properties
147 @tab aaa or aaaAaaaAaaa
148 @tab alignAboveContext, skipBars
149 @item Layout Object Properties
150 @tab aaa or aaa-aaa-aaa
151 @tab direction, beam-thickness
154 As we shall see shortly, the properties of different types of
155 object are modified by different commands, so it is useful to
156 be able to recognise the type of object from the names of its
160 @node Tweaking methods
161 @subsection Tweaking methods
163 @strong{\override command}
165 @cindex override command
168 We have already met the commands @code{\set} and @code{\with},
169 used to change the properties of @strong{contexts} and to remove
170 and add @strong{engravers}, in
171 @ref{Modifying context properties} and @ref{Adding
172 and removing engravers}. We now must meet some more important
175 The command to change the properties of @strong{layout objects} is
176 @code{\override}. Because this command has to modify
177 internal properties deep within LilyPond its syntax is not
178 as simple as the commands you have met so far. It needs to
179 know precisely which property of which object in which context
180 has to be modified, and what its new value is to be. Let's see
183 The general syntax of this command is:
186 \override @emph{context}.@emph{layout_object}
187 #'@emph{layout_property} = #@emph{value}
191 This will set the property with the name @emph{layout_property}
192 of the layout object with the name
193 @emph{layout_object}, which is a member of the @emph{context}
194 context, to the value @emph{value}.
196 The @emph{context} can be omitted (and usually is) when the
197 required context is unambiguously implied and is one of lowest
198 level contexts, i.e., @code{Voice}, @code{ChordNames} or
199 @code{Lyrics}, and we shall omit it in many of the following
200 examples. We shall see later when it must be specified.
202 Later sections deal comprehensively with properties and their
203 values, but to illustrate the format and use of these commands
204 we shall use just a few simple properties and values which are
207 For now, don't worry about the @code{#'}, which must precede the
208 layout property, and the @code{#}, which must precede the value.
209 These must always be present in exactly this form. This is the
210 most common command used in tweaking, and most of the rest of
211 this chapter will be directed to presenting examples of how it is
212 used. Here is a simple example to change the color of the
215 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
217 \override NoteHead #'color = #red
219 \override NoteHead #'color = #green
223 @strong{\revert command}
225 @cindex revert command
228 Once overridden, the property retains its new value until it is
229 overridden again or a @code{\revert} command is encountered.
230 The @code{\revert} command has the following syntax and causes
231 the value of the property to revert to its original default
232 value; note, not its previous value if several @code{\override}
233 commands have been issued.
236 \revert @emph{context}.@emph{layout_object} #'@emph{layout_property}
239 Again, just like @emph{context} in the @code{\override} command,
240 @emph{context} is often not needed. It will be omitted
241 in many of the following examples. Here we revert the color
242 of the note head to the default value for the final two notes:
244 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
246 \override NoteHead #'color = #red
248 \override NoteHead #'color = #green
250 \revert NoteHead #'color
254 @strong{\once prefix}
256 Both the @code{\override} and the @code{\set} commands may be
257 prefixed by @code{\once}. This causes the following
258 @code{\override} or @code{\set} command to be effective only
259 during the current musical moment before the property reverts
260 back to its default value. Using the same example, we can
261 change the color of a single note like this:
263 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
265 \once \override NoteHead #'color = #red
267 \once \override NoteHead #'color = #green
271 @strong{\overrideProperty command}
273 @cindex overrideProperty command
274 @funindex \overrideProperty
276 There is another form of the override command,
277 @code{\overrideProperty}, which is occasionally required.
278 We mention it here for completeness, but for details see
279 @ruser{Difficult tweaks}.
280 @c Maybe explain in a later iteration -td
282 @strong{\tweak command}
284 @cindex tweak command
287 The final tweaking command which is available is @code{\tweak}.
288 This should be used to change the properties of objects which
289 occur at the same musical moment, such as the notes within a
290 chord. Using @code{\override} would affect all the notes
291 within a chord, whereas @code{\tweak} affects just the following
292 item in the input stream.
294 Here's an example. Suppose we wish to change the size of the
295 middle note (the E) in a C major chord. Let's first see what
296 @code{\once \override} would do:
298 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
300 \once \override NoteHead #'font-size = #-3
305 We see the override affects @emph{all} the notes in the chord.
306 This is because all the notes of a chord occur at the same
307 @emph{musical moment}, and the action of @code{\once} is to
308 apply the override to all layout objects of the type specified
309 which occur at the same musical moment as the @code{\override}
312 The @code{\tweak} command operates in a different way. It acts
313 on the immediately following item in the input stream. However,
314 it is effective only on objects which are created directly from
315 the input stream, essentially note heads and articulations.
316 (Objects such as stems and accidentals are created later and
317 cannot be tweaked in this way). Furthermore, when it is applied
318 to note heads these @emph{must} be within a chord, i.e., within
319 single angle brackets, so to tweak a single note the @code{\tweak}
320 command must be placed inside single angle brackets with the
323 So to return to our example, the size of the middle note of
324 a chord would be changed in this way:
326 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
328 <c \tweak #'font-size #-3 e g>4
331 Note that the syntax of @code{\tweak} is different from that
332 of the @code{\override} command. Neither the context nor the
333 layout object should be specified; in fact, it would generate
334 an error to do so. These are both implied by the following
335 item in the input stream. So the general syntax of the
336 @code{\tweak} command is simply:
339 \tweak #'@emph{layout_property} = #@emph{value}
342 A @code{\tweak} command can also be used to modify just one in
343 a series of articulations, as shown here:
345 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
347 -\tweak #'color #red ^Red
348 -\tweak #'color #green _Green
351 Note that the @code{\tweak} command must be preceded by an
352 articulation mark as if it were an articulation itself.
354 The @code{\tweak} command must also be used to change the
355 appearance of one of a set of nested tuplets which begin at the
356 same musical moment. In the following example, the long tuplet
357 bracket and the first of the three short brackets begin at the
358 same musical moment, so any @code{\override} command would apply
359 to both of them. In the example, @code{\tweak} is used to
360 distinguish between them. The first @code{\tweak} command
361 specifies that the long tuplet bracket is to be placed above the
362 notes and the second one specifies that the tuplet number is to be
363 printed in red on the first short tuplet bracket.
365 @lilypond[quote,ragged-right,verbatim,fragment,relative=2]
366 \tweak #'direction #up
369 \times 2/3 { c8[ c8 c8] }
370 \times 2/3 { c8[ c8 c8] }
371 \times 2/3 { c8[ c8 c8] }
375 You can find more details of the @code{\tweak} command in
376 @ruser{Objects connected to the input}.
379 @node The Internals Reference manual
380 @section The Internals Reference manual
382 @cindex Internals Reference
385 * Properties of layout objects::
386 * Properties found in interfaces::
387 * Types of properties::
390 @node Properties of layout objects
391 @subsection Properties of layout objects
393 @cindex properties of layout objects
394 @cindex properties of grobs
395 @cindex grobs, properties of
396 @cindex layout objects, properties of
398 Suppose you have a slur in a score which, to your mind,
399 appears too thin and you'd like to draw it a little heavier.
400 How do you go about doing this? You know from the statements
401 earlier about the flexibility of LilyPond that such a thing
402 should be possible, and you would probably guess that an
403 @code{\override} command would be needed. But is there a
404 heaviness property for a slur, and if there is, how might it
405 be modified? This is where the Internals Reference manual
406 comes in. It contains all the information you might need to
407 construct this and all other @code{\override} commands.
409 Before we look at the Internals Reference a word of warning.
410 This is a @strong{reference} document, which means there is
411 little or no explanation contained within it: its purpose is
412 to present information precisely and concisely. This
413 means it might look daunting at first sight. Don't worry!
414 The guidance and explanation presented here will enable you
415 to extract the information from the Internals Reference for
416 yourself with just a little practice.
418 @cindex override example
419 @cindex Internals Reference, example of using
421 Let's use a concrete example with a simple fragment of real
424 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
429 g[( e]) e d[( f]) a |
433 The man who feels love's sweet e -- mo -- tion
438 Suppose now that we decide we would like the slurs to be a
439 little heavier. Is this possible? The slur is certainly a
440 layout object, so the question is, @q{Is there a property
441 belonging to a slur which controls the heaviness?} To answer
442 this we must look in the Internals Reference, or IR for short.
444 The IR for the version of LilyPond you are using may be found
445 on the LilyPond website at @uref{http://lilypond.org}. Go to the
446 documentation page and click on the Internals Reference link.
447 For learning purposes you should use the standard html version,
448 not the @q{one big page} or the PDF. For the next few
449 paragraphs to make sense you will need to actually do this
452 Under the heading @strong{Top} you will see five links. Select
453 the link to the @emph{Backend}, which is where information about
454 layout objects is to be found. There, under the heading
455 @strong{Backend}, select the link to @emph{All layout objects}.
456 The page that appears lists all the layout objects used in your
457 version of LilyPond, in alphabetic order. Select the link to
458 Slur, and the properties of Slurs are listed.
460 (An alternative way of finding this page is from the Notation
461 Reference. On one of the pages that deals with slurs you may
462 find a link to the Internals Reference. This link will
463 take you directly to this page, but often it is easier to go
464 straight to the IR and search there.)
466 This Slur page in the IR tells us first that Slur objects are
468 Slur_engraver. Then it lists the standard settings. Note
469 these are @strong{not} in alphabetic order. Browse down
470 them looking for a property that might control the heaviness
471 of slurs, and you should find
474 @code{thickness} (number)
476 Line thickness, generally measured in @code{line-thickness}
479 This looks a good bet to change the heaviness. It tells us that
480 the value of @code{thickness} is a simple @emph{number},
481 that the default value is 1.2, and that the units are
482 in another property called @code{line-thickness}.
484 As we said earlier, there are few to no explanations in the IR,
485 but we already have enough information to try changing the
486 slur thickness. We see that the name of the layout object
487 is @code{Slur}, that the name of the property to change is
488 @code{thickness} and that the new value should be a number
489 somewhat larger than 1.2 if we are to make slurs thicker.
491 We can now construct the @code{\override} command by simply
492 substituting the values we have found for the names, omitting
493 the context. Let's use a very large value for the thickness
494 at first, so we can be sure the command is working. We get:
497 \override Slur #'thickness = #5.0
500 Don't forget the @code{#'} preceding the
501 property name and and @code{#} preceding the new value!
503 The final question is, @q{Where should this command be
504 placed?} While you are unsure and learning, the best
505 answer is, @q{Within the music, before the first slur and
506 close to it.} Let's do that:
508 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
512 % Increase thickness of all following slurs from 1.2 to 5.0
513 \override Slur #'thickness = #5.0
515 g[( e]) e d[( f]) a |
519 The man who feels love's sweet e -- mo -- tion
525 and we see that the slur is indeed heavier.
527 So this is the basic way of constructing @code{\override}
528 commands. There are a few more complications that we
529 shall meet in later sections, but you now know all the
530 essentials required to make up your own -- but you will
531 still need some practice. This is provided in the examples
534 @subheading Finding the context
535 @cindex context, finding
537 But first, what if we had needed to specify the Context?
538 What should it be? We could guess that slurs are in
539 the Voice context, as they are clearly closely associated
540 with individual lines of music, but can we be sure? To
541 find out, go back to the top of the IR page describing the
542 Slur, where it says @q{Slur objects are created by: Slur
543 engraver}. So slurs will be created in whichever context
544 the @code{Slur_engraver} is in. Follow the link to the
545 @code{Slur_engraver} page. At the very bottom it tells
546 us that @code{Slur_engraver} is part of five Voice contexts,
547 including the standard voice context, @code{Voice}, so our
548 guess was correct. And because @code{Voice} is one of the
549 lowest level contexts which is implied unambiguously by
550 the fact that we are entering notes, we can omit it in this
553 @subheading Overriding once only
555 @cindex overriding once only
556 @cindex once override
559 As you can see, @emph{all} the slurs are thicker in the
560 final example above. But what if we
561 wanted just the first slur to be thicker? This is achieved
562 with the @code{\once} command. Placed immediately before
563 the @code{\override} command it causes it to change only the
564 slur which begins on the @strong{immediately following} note.
566 immediately following note does not begin a slur the command
567 has no effect at all -- it is not remembered until a slur
568 is encountered, it is simply discarded. So the command with
570 repositioned as follows:
572 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
577 % Increase thickness of immediately following slur only
578 \once \override Slur #'thickness = #5.0
580 g[( e]) e d[( f]) a |
584 The man who feels love's sweet e -- mo -- tion
590 Now only the first slur is made heavier.
592 The @code{\once} command can also be used before the @code{\set}
595 @subheading Reverting
598 @cindex default properties, reverting
601 Finally, what if we wanted just the first two slurs to be
602 heavier? Well, we could use two commands, each preceded by
603 @code{\once} placed immediately before each of the notes where
606 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
611 % Increase thickness of immediately following slur only
612 \once \override Slur #'thickness = #5.0
614 % Increase thickness of immediately following slur only
615 \once \override Slur #'thickness = #5.0
616 g[( e]) e d[( f]) a |
620 The man who feels love's sweet e -- mo -- tion
626 or we could omit the @code{\once} command and use the
627 @code{\revert} command
628 to return the @code{thickness} property to its default value
629 after the second slur:
631 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
636 % Increase thickness of all following slurs from 1.2 to 5.0
637 \override Slur #'thickness = #5.0
640 % Revert thickness of all following slurs to default of 1.2
641 \revert Slur #'thickness
646 The man who feels love's sweet e -- mo -- tion
652 The @code{\revert} command can be used to return any property
653 changed with @code{\override} back to its default value.
654 You may use whichever method best suits what you want to do.
656 That concludes our introduction to the IR, and the basic
657 method of tweaking. Several examples follow in the later
658 sections of this Chapter, partly to introduce you to some of the
659 additional features of the IR, and partly to give you more
660 practice in extracting information from it. These examples will
661 contain progressively fewer words of guidance and explanation.
663 @node Properties found in interfaces
664 @subsection Properties found in interfaces
666 @cindex interface properties
667 @cindex properties in interfaces
669 Suppose now that we wish to print the lyrics in italics. What
670 form of @code{\override} command do we need to do this?
671 We first look in the IR page listing @q{All layout objects}, as
672 before, and look for an object that might control lyrics. We
673 find @code{LyricText}, which looks right. Clicking on this shows
674 the settable properties for lyric text. These include the
675 @code{font-series} and @code{font-size}, but nothing that might
676 give an italic shape.
677 This is because the shape property is one that is common to all
678 font objects, so, rather than including it in every layout
679 object, it is grouped together with other similar common
680 properties and placed in an @strong{Interface}, the
681 @code{font-interface}.
683 So now we need to learn how to find the properties of interfaces,
684 and to discover what objects use these interface properties.
686 Look again at the IR page which describes LyricText. At the
687 bottom of the page is a list of clickable (in the html versions
688 of the IR) interfaces which LyricText supports. The list has
689 seven items, including @code{font-interface}.
690 Clicking on this brings up the properties associated
691 with this interface, which are also properties of all the objects
692 which support it, including LyricText.
694 Now we see all the user-settable properties which control fonts,
695 including @code{font-shape(symbol)}, where @code{symbol} can be
696 set to @code{upright}, @code{italics} or @code{caps}.
698 You will notice that that @code{font-series} and @code{font-size}
699 are also listed there.
700 This immediately raises the question: Why are the common font
701 properties @code{font-series} and @code{font-size} listed under
702 @code{LyricText} as well as under the interface
703 @code{font-interface} but @code{font-shape} is not? The answer
704 is that @code{font-series} and @code{font-size} are changed
705 from their global default values when a @code{LyricText} object
706 is created, but @code{font-shape} is not. The entries in
707 @code{LyricText} then tell you the values for those two
708 properties which apply to @code{LyricText}. Other objects
709 which support @code{font-interface} will set these
710 properties diferently when they are created.
712 Let's see if we can now construct the @code{\override} command
713 to change the lyrics to italics. The object is @code{LyricText},
714 the property is @code{font-shape} and the value is
715 @code{italic}. As before, we'll omit the context.
717 As an aside, although it is an important one, note that because
719 @code{font-shape} are symbols they must be introduced with a
720 single apostrophe, @code{'}. That is why apostrophes
721 are needed before @code{thickness} in the earlier example
722 and @code{font-shape}. These are both symbols too.
723 Symbols are special names which are known internally to
724 LilyPond. Some of them are the names of properties,
725 like @code{thickness} or @code{font-shape}, others are in
726 effect special values that can be given to properties, like
727 @code{italic}. Note the distinction from arbitary
728 text strings, which would appear as @code{"a text string"}.
730 Ok, so the @code{\override} command we need to print the lyrics
734 \override LyricText #'font-shape = #'italic
738 and this should be placed just in front of and close to the
739 lyrics which it should affect, like this:
741 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
746 g[( e]) e d[( f]) a |
750 \override LyricText #'font-shape = #'italic
751 The man who feels love's sweet e -- mo -- tion
757 and the lyrics are all printed in italics.
759 @subheading Specifying the context in lyric mode
760 @cindex context, specifying in lyric mode
762 In the case of lyrics, if you try specifying the context in the
763 format given earlier the command will fail. A syllable
764 entered in lyricmode is terminated by either a space,
765 a newline or a digit. All other characters are included
766 as part of the syllable. For this reason a space or newline
767 must appear before the terminating @code{@}} to prevent it being
768 included as part of the final syllable. Similarly,
769 spaces must be inserted before and after the
770 period or dot, @q{.}, separating the context name from the
771 object name, as otherwise the two names are run together and
772 the interpreter cannot recognise them. So the command should be:
775 \override Lyrics . LyricText #'font-shape = #'italic
778 @warning{In lyrics always leave whitespace between the final
779 syllable and the terminating brace.}
781 @warning{In overrides in lyrics always place spaces around
782 the dot between the context name and the object name.}
784 @node Types of properties
785 @subsection Types of properties
787 @cindex Property types
789 So far we have seen two types of property: @code{number} and
790 @code{symbol}. To be valid, the value given to a property
791 must be of the correct type and obey the rules for that type.
792 The type of property is always shown in brackets after the
793 property name in the IR. Here is a list of the types you may
794 need, together with the rules for that type, and some examples.
795 You must always add a hash symbol, @code{#}, of course,
796 to the front of these values when they are entered in the
797 @code{\override} command.
799 @multitable @columnfractions .2 .45 .35
800 @headitem Property type
804 @tab Either True or False, represented by #t or #f
805 @tab @code{#t}, @code{#f}
806 @item Dimension (in staff space)
807 @tab A positive decimal number (in units of staff space)
808 @tab @code{2.5}, @code{0.34}
810 @tab A valid direction constant or its numerical equivalent
811 @tab @code{#LEFT}, @code{#CENTER}, @code{#UP},
814 @tab A positive whole number
815 @tab @code{3}, @code{1}
817 @tab A bracketed set of items separated by spaces,
818 preceded by an apostrophe
819 @tab @code{'(left-edge staff-bar)}, @code{'(1)},
820 @code{'(1.0 0.25 0.5)}
822 @tab Any valid markup
823 @tab @code{\markup @{ \italic "cresc." @}}
825 @tab A fraction of a whole note constructed with the
827 @tab @code{(ly:make-moment 1 4)},
828 @code{(ly:make-moment 3 8)}
830 @tab Any positive or negative decimal value
831 @tab @code{3.5}, @code{-2.45}
832 @item Pair (of numbers)
833 @tab Two numbers separated by a @q{space . space} and enclosed
834 in brackets preceded by an apostrophe
835 @tab @code{'(2 . 3.5)}, @code{'(0.1 . -3.2)}
837 @tab Any of the set of permitted symbols for that property,
838 preceded by an apostrophe
839 @tab @code{'italic}, @code{'inside}
841 @tab A procedure or @code{#f} (to cause no action)
842 @tab @code{bend::print}, @code{ly:text-interface::print},
845 @tab A list of three items enclosed in brackets and preceded
846 by a hash sign, @code{#}.
847 @tab @code{#(#t #t #f)}
850 @node Appearance of objects
851 @section Appearance of objects
853 Let us now put what we have learnt into practice with a few
854 examples which show how tweaks may be used to change the
855 appearance of the printed music.
858 * Visibility and color of objects::
860 * Length and thickness of objects::
863 @node Visibility and color of objects
864 @subsection Visibility and color of objects
866 In the educational use of music we might wish to print a score
867 with certain elements omitted as an exercise for the student,
868 who is required to supply them. As a simple example,
869 let us suppose the exercise is to supply the missing bar lines
870 in a piece of music. But the bar lines are normally inserted
871 automatically. How do we prevent them printing?
873 Before we tackle this, let us remember that object properties
874 are grouped in what are called @emph{interfaces} -- see
875 @ref{Properties found in interfaces}. This is simply to
876 group together those properties that are commonly required
877 together -- if one of them is required for an object, so are
878 the others. Some objects then need the properties in some
879 interfaces, others need them from other interfaces. The
880 interfaces which contain the properties required by a
881 particular grob are listed in the IR at the bottom of the
882 page describing that grob, and those properties may be
883 viewed by looking at those interfaces.
885 We explained how to find information about grobs in
886 @ref{Properties of layout objects}. Using the same approach,
887 we go to the IR to find the layout object which prints
888 bar lines. Going via @emph{Backend} and @emph{All layout objects}
890 is a layout object called @code{BarLine}. Its properties include
891 two that control its visibility: @code{break-visibility} and
892 @code{stencil}. Barline also supports a number of interfaces,
893 including the @code{grob-interface}, where we find the
894 @code{transparent} and the @code{color} properties. All
895 of these can affect the visibility of bar lines (and, of course,
896 by extension, many other layout objects too.) Let's consider
897 each of these in turn.
900 @cindex stencil property
902 This property controls the appearance of the bar lines by specifying
903 the symbol (glyph) which should be printed. In common
904 with many other properties, it can be set to print nothing by
905 setting its value to @code{#f}. Let's try it, as before, omitting
906 the implied Context, @code{Voice}:
908 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
911 \override BarLine #'stencil = ##f
918 The bar lines are still printed. What is wrong? Go back to the
919 IR and look again at the page giving the properties of BarLine.
920 At the top of the page it says @qq{Barline objects are created
921 by: Bar_engraver}. Go to the @code{Bar_engraver} page.
923 it gives a list of Contexts in which the bar engraver operates.
924 All of them are of the type @code{Staff}, so the reason the
925 @code{\override} command failed to work as expected is because
926 @code{Barline} is not in the default @code{Voice} context.
928 is specified wrongly, the command simply does not work. No
929 error message is produced, and nothing is logged in the log
930 file. Let's try correcting it by adding the correct context:
932 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
935 \override Staff.BarLine #'stencil = ##f
942 Now the bar lines have vanished.
944 @subheading break-visibility
946 @cindex break-visibility property
948 We see from the @code{BarLine} properties in the IR that the
949 @code{break-visibility} property requires a vector of three
951 These control respectively whether bar lines are printed at
952 the end of a line, in the middle of lines, and at the beginning
953 of lines. For our example we want all bar lines to be suppressed,
954 so the value we need is @code{#(#f #f #f)}.
955 Let's try that, remembering
956 to include the @code{Staff} context. Note also that in writing
957 this value we have two hash signs before the opening bracket.
958 One is required as part of the value to introduce a vector,
959 and one is required, as always, to precede the value itself in
960 the @code{\override} command.
962 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
965 \override Staff.BarLine #'break-visibility = ##(#f #f #f)
972 And we see this too removes all the bar lines.
974 @subheading transparent
975 @cindex transparent property
977 We see from the properties specified in the @code{grob-interface}
978 page in the IR that the @code{transparent} property is a boolean.
980 should be set to @code{#t} to make the grob transparent.
981 In this next example let us make the time signature invisible
982 rather than the bar lines.
983 To do this we need to find the grob name for the time signature.
985 the @q{All layout objects} page in the IR to find the properties
986 of the @code{TimeSignature} layout object. This is produced by
987 the @code{Time_signature_engraver} which you can check also lives
988 in the @code{Staff} context and also supports the
989 @code{grob-interface}. So the command to make the time signature
992 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
995 \override Staff.TimeSignature #'transparent = ##t
1003 The time signature is gone, but this command leaves a gap where
1004 the time signature should be. Maybe this is what is wanted for
1005 an exercise for the student to fill it in, but in other
1006 circumstances a gap might be undesirable. To remove it, the
1007 stencil for the time signature should be set to @code{#f}
1010 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1013 \override Staff.TimeSignature #'stencil = ##f
1015 g, a16 b8 c d4 e16 |
1021 and the difference is obvious: setting the stencil to @code{#f}
1022 removes the object entirely; making the object @code{transparent}
1023 leaves it where it is, but makes it invisible.
1026 @cindex color property
1028 Finally we could make the bar lines invisible by coloring
1029 them white. The @code{grob-interface} specifies that the
1030 color property value is a list, but there is no
1031 explanation of what that list should be. The list it
1032 requires is actually a list of values in internal units,
1033 but, to avoid having to know what these are, several ways
1034 are provided to specify colors. The first way is to use one
1035 of the @q{normal} colours listed in the first table in
1036 @ruser{List of colors}. To set the bar lines to white
1039 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1042 \override Staff.BarLine #'color = #white
1044 g, a16 b8 c d4 e16 |
1050 and again, we see the bar lines are not visible. Note that
1051 @emph{white} is not preceded by an apostrophe -- it is not
1052 a symbol, but a @emph{function}. When called, it provides
1053 the list of internal values required to set the color to
1054 white. The other colors in the normal list are functions
1055 too. To convince yourself this is working you might like
1056 to change the color to one of the other functions in the
1062 The second way of changing the color is to use the list of
1063 X11 color names in the second list in @ruser{List of colors}.
1064 However, these must be preceded by another function, which
1065 converts X11 color names into the list of internal values,
1066 @code{x11-color}, like this:
1068 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1071 \override Staff.BarLine #'color = #(x11-color 'white)
1073 g, a16 b8 c d4 e16 |
1079 Note that in this case the function @code{x11-color} takes
1080 a symbol as an argument, so the symbol must be preceded by
1081 an apostrophe and the two enclosed in brackets.
1086 There is yet a third function, one which converts RGB values into
1087 internal colors -- the @code{rgb-color} function. This takes
1088 three arguments giving the intensities of the red, green and
1089 blue colors. These take values in the range 0 to 1. So to
1090 set the color to red the value should be @code{(rgb-color 1 0 0)}
1091 and to white it should be @code{(rgb-color 1 1 1)}:
1093 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1096 \override Staff.BarLine #'color = #(rgb-color 1 1 1)
1098 g, a16 b8 c d4 e16 |
1103 Finally, there is also a grey scale available as part of the
1104 X11 set of colors. These range from black, @code{'grey0'},
1105 to white, @code{'grey100}, in steps of 1. Let's illustrate
1106 this by setting all the layout objects in our example to
1107 various shades of grey:
1109 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1112 \override Staff.StaffSymbol #'color = #(x11-color 'grey30)
1113 \override Staff.TimeSignature #'color = #(x11-color 'grey60)
1114 \override Staff.Clef #'color = #(x11-color 'grey60)
1115 \override Voice.NoteHead #'color = #(x11-color 'grey85)
1116 \override Voice.Stem #'color = #(x11-color 'grey85)
1117 \override Staff.BarLine #'color = #(x11-color 'grey10)
1119 g, a16 b8 c d4 e16 |
1125 Note the contexts associated with each of the layout objects.
1126 It is important to get these right, or the commands will not
1127 work! Remember, the context is the one in which the appropriate
1128 engraver is placed. The default context for engravers can be
1129 found by starting from the layout object, going from there to
1130 the engraver which produces it, and on the engraver page in the
1131 IR it tells you in which context the engraver will normally be
1135 @node Size of objects
1136 @subsection Size of objects
1138 Let us begin by looking again at the earlier example
1139 see @ref{Nesting music expressions}) which showed
1140 how to introduce a new temporary staff, as in an @rglos{ossia}.
1142 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1143 \new Staff ="main" {
1150 alignAboveContext = "main" }
1158 Ossia are normally written without clef and time signature, and
1159 are usually printed slightly smaller than the main staff. We
1160 already know now how to remove the clef and time signature --
1161 we simply set the stencil of each to @code{#f}, as follows:
1163 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1164 \new Staff ="main" {
1171 alignAboveContext = "main"
1174 \override Staff.Clef #'stencil = ##f
1175 \override Staff.TimeSignature #'stencil = ##f
1185 where the extra pair of braces after the @code{\with} clause are
1186 required to ensure the enclosed overrrides and music are applied
1189 But what is the difference between modifying the staff context by
1190 using @code{\with} and modifying the stencils of the clef and the
1191 time signature with \override? The main difference is that
1192 changes made in a @code{\with} clause are made at the time the
1193 context is created, and remain in force as the @strong{default}
1194 values for the duration of that context, whereas
1195 @code{\set} or @code{\override} commands embedded in the
1196 music are dynamic -- they make changes synchronised with
1197 a particular point in the music. If changes are unset or
1198 reverted using @code{\unset} or @code{\revert} they return to
1199 their default values, which will be the ones set in the
1200 @code{\with} clause, or if none have been set there, the normal
1203 Some context properties
1204 can be modified only in @code{\with} clauses. These are those
1205 properties which cannot sensibly be changed after the context
1206 has been created. @code{alignAboveContext} and its partner,
1207 @code{alignBelowContext}, are two such properties -- once the
1208 staff has been created its alignment is decided and it would
1209 make no sense to try to change it later.
1211 The default values of layout object properties can also be set
1212 in @code{\with} clauses. Simply use the normal @code{\override}
1213 command leaving out the context name, since this is unambiguously
1214 defined as the context which the @code{\with} clause is modifying.
1215 If fact, an error will be generated if a context is specified
1218 So we could replace the example above with
1220 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1221 \new Staff ="main" {
1228 alignAboveContext = "main"
1229 % Don't print clefs in this staff
1230 \override Clef #'stencil = ##f
1231 % Don't print time signatures in this staff
1232 \override TimeSignature #'stencil = ##f
1241 Finally we come to changing the size of layout objects.
1243 Some layout objects are created as glyphs selected from
1244 a typeface font. These include note heads, accidentals, markup,
1245 clefs, time signatures, dynamics and lyrics.
1246 Their size is changed by modifying the
1247 @code{font-size} property, as we shall shortly see. Other
1248 layout objects such as slurs and ties -- in general, spanner
1249 objects -- are drawn individually, so there is no
1251 associated with them. These objects generally derive their
1252 size from the objects to which they are attached, so usually
1253 there is no need to change their size manually. Still other
1254 properties such as the length of stems and bar lines, thickness
1255 of beams and other lines, and the separation of staff lines all
1256 need to be modified in special ways.
1258 Returning to the ossia example, let us first change the font-size.
1259 We can do this in two ways. We can either change the size of the
1260 fonts of each object type, like @code{NoteHead}s with commands
1264 \override NoteHead #'font-size = #-2
1267 or we can change the size of all fonts by setting a special
1268 property, @code{fontSize}, using @code{\set}, or by including
1269 it in a @code{\with} clause (but without the @code{\set}).
1275 Both of these statements would cause the font size to be reduced
1276 by 2 steps from its previous value, where each
1277 step reduces or increases the size by approximately 12%.
1279 Let's try it in our ossia example:
1281 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1282 \new Staff ="main" {
1289 alignAboveContext = "main"
1290 \override Clef #'stencil = ##f
1291 \override TimeSignature #'stencil = ##f
1292 % Reduce all font sizes by ~24%
1302 This is still not quite right. The note heads and flags are
1303 smaller, but the stems are too long in proportion and the
1304 staff lines are spaced too widely apart. These need to be
1305 scaled down in proportion to the font reduction. The next
1306 sub-section discusses how this is done.
1308 @node Length and thickness of objects
1309 @subsection Length and thickness of objects
1315 @cindex size, changing
1316 @cindex stem length, changing
1317 @cindex staff line spacing, changing
1319 Distances and lengths in LilyPond are generally measured in
1320 staff-spaces, the distance between adjacent lines in the staff,
1321 (or occasionally half staff spaces) while most @code{thickness}
1322 properties are measured in units of an internal property called
1323 @code{line-thickness.} For example, by default, the lines of
1324 hairpins are given a thickness of 1 unit of @code{line-thickness},
1325 while the @code{thickness} of a note stem is 1.3. Note, though,
1326 that some thickness properties are different; for example, the
1327 thickness of beams is measured in staff-spaces.
1329 So how are lengths to be scaled in proportion to the font size?
1330 This can be done with the help of a special function called
1331 @code{magstep} provided for exactly this purpose. It takes
1332 one argument, the change in font size (#-2 in the example above)
1333 and returns a scaling factor suitable for reducing other
1334 objects in proportion. It is used like this:
1336 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1337 \new Staff ="main" {
1344 alignAboveContext = "main"
1345 \override Clef #'stencil = ##f
1346 \override TimeSignature #'stencil = ##f
1348 % Reduce stem length and line spacing to match
1349 \override StaffSymbol #'staff-space = #(magstep -2)
1359 Since the length of stems and many other length-related properties
1360 are always calculated relative to the
1361 value of the @code{staff-space} property these are automatically
1362 scaled down in length too. Note that this affects only the
1363 vertical scale of the ossia -- the horizontal scale is determined
1364 by the layout of the main music in order to remain synchronised
1365 with it, so it is not affected by any of these changes in size.
1366 Of course, if the scale of all the main music were changed in this
1367 way then the horizontal spacing would be affected. This is
1368 discussed later in the layout section.
1370 This, then, completes the creation of an ossia. The sizes and
1371 lengths of all other objects may be modified in analogous ways.
1373 For small changes in scale, as in the example above, the
1374 thickness of the various drawn lines such as bar lines,
1375 beams, hairpins, slurs, etc does not usually require global
1376 adjustment. If the thickness of any particular layout object
1377 needs to be adjusted this can be best achieved by overriding its
1378 @code{thickness} property. An example of changing the thickness
1379 of slurs was shown above in @ref{Properties of layout objects}.
1380 The thickness of all drawn objects (i.e., those not produced
1381 from a font) may be changed in the same way.
1384 @node Placement of objects
1385 @section Placement of objects
1388 * Automatic behaviour::
1389 * Within-staff objects::
1390 * Outside staff objects::
1394 @node Automatic behaviour
1395 @subsection Automatic behaviour
1397 There are some objects in musical notation that belong to
1398 the staff and there are other objects that should be
1399 placed outside the staff. These are called within-staff
1400 objects and outside-staff objects respectively.
1402 Within-staff objects are those that are located on the staff
1403 -- note heads, stems, accidentals, etc. The positions of
1404 these are usually fixed by the music itself -- they are
1405 vertically positioned on specific lines of the staff or are
1406 tied to other objects that are so positioned. Collisions of
1407 note heads, stems and accidentals in closely set chords are
1408 normally avoided automatically. There are commands and
1409 overrides which can modify this automatic behaviour, as we
1412 Objects belonging outside the staff include things such as
1413 rehearsal marks, text and dynamic markings. LilyPond's rule for
1414 the vertical placement of outside-staff objects is to place them
1415 as close to the staff as possible but not so close that they
1416 collide with any other object. LilyPond uses the
1417 @code{outside-staff-priority} property to determine the order in
1418 which the objects should be placed, as follows.
1420 First, LilyPond places all the within-staff objects.
1421 Then it sorts the outside-staff objects according to their
1422 @code{outside-staff-priority}. The outside-staff objects are
1423 taken one by one, beginning with the object with the lowest
1424 @code{outside-staff-priority}, and placed so that they do not
1425 collide with any objects that have already been placed. That is,
1426 if two outside-staff grobs are competing for the same space, the
1427 one with the lower @code{outside-staff-priority} will be placed
1428 closer to the staff. If two objects have the same
1429 @code{outside-staff-priority} the one encountered first will be
1430 placed closer to the staff.
1432 In the following example all the markup texts have the same
1433 priority (since it is not explicity set). Note that @q{Text3}
1434 is automatically positioned close to the staff again, nestling
1437 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1444 Staves are also positioned, by default, as closely together as
1445 possible (subject to a minimum separation). If notes project
1446 a long way towards an adjacent staff they will force the
1447 staves further apart only if an overlap of the notation
1448 would otherwise occur. The following example demonstrates
1449 this @q{nestling} of the notes on adjacent staves:
1451 @lilypond[quote,ragged-right,verbatim]
1454 \relative c' { c a, }
1457 \relative c'''' { c a, }
1463 @node Within-staff objects
1464 @subsection Within-staff objects
1466 We have already seen how the commands @code{\voiceXXX} affect
1467 the direction of slurs, ties, fingering and
1468 everything else which depends on the direction of the stems.
1469 These commands are essential when writing polyphonic music to
1470 permit interweaving melodic lines to be distinguished.
1471 But occasionally it may be necessary to override this automatic
1472 behaviour. This can be done for whole sections of music or even
1473 for an individual note. The property which controls this
1474 behaviour is the @code{direction} property of each layout object.
1475 We first explain what this does, and then introduce a number of
1476 ready-made commands which avoid your having to code explicit
1477 overrides for the more common modifications.
1479 Some layout objects like slurs and ties curve, bend or point
1480 either up or down; others like stems and flags also move to
1481 right or left when they point up or down. This is controlled
1482 automatically when @code{direction} is set.
1484 The following example shows in bar 1 the default behaviour of
1486 with those on high notes pointing down and those on low notes
1487 pointing up, followed by four notes with all stems forced down,
1488 four notes with all stems forced up, and finally four notes
1489 reverted back to the default behaviour.
1491 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1493 \override Stem #'direction = #DOWN
1495 \override Stem #'direction = #UP
1497 \revert Stem #'direction
1501 Here we use the constants @code{DOWN} and @code{UP}.
1502 These have the values @code{-1} and @code{+1} respectively, and
1503 these numerical values may be used instead. The value @code{0}
1504 may also be used in some cases. It is simply treated as meaning
1505 @code{UP} for stems, but for some objects it means @q{center}.
1506 There is a constant, @code{CENTER} which has the value @code{0}.
1508 However, these explicit overrides are not usually used, as there
1509 are simpler equivalent predefined commands available.
1510 Here is a table of the commonest. The meaning of each is stated
1511 where it is not obvious.
1513 @multitable @columnfractions .2 .2 .2 .4
1518 @item @code{\arpeggioDown}
1519 @tab @code{\arpeggioUp}
1520 @tab @code{\arpeggioNeutral}
1521 @tab Arrow is at bottom, at top, or no arrow
1522 @item @code{\dotsDown}
1524 @tab @code{\dotsNeutral}
1525 @tab Direction of movement to avoid staff lines
1526 @item @code{\dynamicDown}
1527 @tab @code{\dynamicUp}
1528 @tab @code{\dynamicNeutral}
1530 @item @code{\phrasingSlurDown}
1531 @tab @code{\phrasingSlurUp}
1532 @tab @code{\phrasingSlurNeutral}
1533 @tab Note: distinct from slur commands
1534 @item @code{\slurDown}
1536 @tab @code{\slurNeutral}
1538 @item @code{\stemDown}
1540 @tab @code{\stemNeutral}
1542 @item @code{\textSpannerDown}
1543 @tab @code{\textSpannerUp}
1544 @tab @code{\textSpannerNeutral}
1545 @tab Text entered as spanner is below/above staff
1546 @item @code{\tieDown}
1548 @tab @code{\tieNeutral}
1550 @item @code{\tupletDown}
1551 @tab @code{\tupletUp}
1552 @tab @code{\tupletNeutral}
1553 @tab Tuplets are below/above notes
1556 Note that these predefined commands may @strong{not} be
1557 preceded by @code{\once}. If you wish to limit the
1558 effect to a single note you must either use the equivalent
1559 @code{\once \override} command or use the predefined command
1560 followed after the affected note by the corresponding
1561 @code{\xxxNeutral} command.
1563 @subheading Fingering
1564 @cindex fingering, placement
1566 The placement of fingering is also affected by the value
1567 of its @code{direction} property, but there are special
1568 commands which allow the fingering of individual notes
1569 of chords to be controlled, with the fingering being placed
1570 above, below, to the left or to the right of each note.
1572 First, here's the effect of @code{direction} on fingering,
1573 the first bar shows the default, then the effect of specifying
1574 @code{DOWN} and @code{UP}:
1576 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1578 \override Fingering #'direction = #DOWN
1580 \override Fingering #'direction = #UP
1584 This is how to control fingering on single notes, but the
1586 property is ignored for chords. Instead, by default, the
1587 fingering is automatically placed both above and below the
1588 notes of a chord, as shown:
1590 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1596 Greater control over the placement of fingering of the
1597 individual notes in a chord is possible by using
1598 the @code{\set fingeringOrientations} command. The format of
1602 @code{\set fingeringOrientations = #'([up] [left/right] [down])}
1606 @code{\set} is used because @code{fingeringOrientations} is a
1607 property of the @code{Voice} context, created and used by the
1608 @code{New_fingering_engraver}.
1610 The property may be set to a list of one to three values.
1611 It controls whether fingerings may be placed above (if
1612 @code{up} appears in the list), below (if @code{down} appears),
1613 to the left (if @code{left} appears, or to the right
1614 (if @code{right} appears). Conversely, if a location is not
1615 listed, no fingering is placed there. LilyPond takes these
1616 contraints and works out the best placement for the fingering
1617 of the notes of the following chords. Note that @code{left} and
1618 @code{right} are mutually exclusive -- fingering may be placed
1619 only on one side or the other, not both.
1621 To control the placement of the fingering of a single note
1622 using this command it is necessary to write it as a single
1623 note chord by placing angle brackets round it.
1625 Here are a few examples:
1627 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1628 \set fingeringOrientations = #'(left)
1630 < c-1 e-2 g-3 b-5 > 4
1631 \set fingeringOrientations = #'(left)
1633 < c-1 e-2 g-3 b-5 > 4
1634 \set fingeringOrientations = #'(up left down)
1636 < c-1 e-2 g-3 b-5 > 4
1637 \set fingeringOrientations = #'(up left)
1639 < c-1 e-2 g-3 b-5 > 4
1640 \set fingeringOrientations = #'(right)
1642 < c-1 e-2 g-3 b-5 > 4
1646 If the fingering seems a little crowded the @code{font-size}
1647 could be reduced. The default value can be seen from the
1648 @code{Fingering} object in the IR to be @code{-5}, so let's
1651 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1652 \override Fingering #'font-size = #-7
1653 \set fingeringOrientations = #'(left)
1655 < c-1 e-2 g-3 b-5 > 4
1656 \set fingeringOrientations = #'(left)
1658 < c-1 e-2 g-3 b-5 > 4
1659 \set fingeringOrientations = #'(up left down)
1661 < c-1 e-2 g-3 b-5 > 4
1662 \set fingeringOrientations = #'(up left)
1664 < c-1 e-2 g-3 b-5 > 4
1665 \set fingeringOrientations = #'(right)
1667 < c-1 e-2 g-3 b-5 > 4
1670 @node Outside staff objects
1671 @subsection Outside staff objects
1673 Outside-staff objects are automatically placed to avoid collisions.
1674 Objects with the lower value of the @code{outside-staff-priority}
1675 property are placed nearer to the staff, and other outside-staff
1676 objects are then raised as far as necessary to avoid collisions.
1677 The @code{outside-staff-priority} is defined in the
1678 @code{grob-interface} and so is a property of all layout objects.
1679 By default it is set to @code{#f} for all within-staff objects,
1680 and to a numerical value appropriate to each outside-staff object
1681 when the object is created. The following table shows
1682 the default numerical values for some of the commonest
1683 outside-staff objects which are, by default, placed in the
1684 @code{Staff} or @code{Voice} contexts.
1686 @multitable @columnfractions .3 .3 .3
1687 @headitem Layout Object
1689 @tab Controls position of:
1690 @item @code{MultiMeasureRestText}
1692 @tab Text over full-bar rests
1693 @item @code{TextScript}
1696 @item @code{OttavaBracket}
1698 @tab Ottava brackets
1699 @item @code{TextSpanner}
1702 @item @code{DynamicLineSpanner}
1704 @tab All dynamic markings
1705 @item @code{VoltaBracketSpanner}
1708 @item @code{TrillSpanner}
1710 @tab Spanning trills
1713 Here is an example showing the default placement of some of
1716 @cindex text spanner
1717 @funindex \startTextSpan
1718 @funindex \stopTextSpan
1719 @cindex ottava bracket
1721 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1722 % Set details for later Text Spanner
1723 \override TextSpanner #'bound-details #'left #'text
1724 = \markup { \small \bold Slower }
1725 % Place dynamics above staff
1727 % Start Ottava Bracket
1732 % Add Dynamic Line Spanner
1738 c\ff c \stopTextSpan
1739 % Stop Ottava Bracket
1744 This example also shows how to create Text Spanners --
1745 text with extender lines above a section of music. The
1746 spanner extends from the @code{\startTextSpan} command to
1747 the @code{\stopTextSpan} command, and the format of the
1748 text is defined by the @code{\override TextSpanner} command.
1749 For more details see @ruser{Text spanners}.
1751 It also shows how ottava brackets are created.
1753 Note that bar numbers, metronome marks and rehearsal marks
1754 are not shown. By default these are created in the
1755 @code{Score} context and their @code{outside-staff-priority}
1756 is ignored relative to the layout objects which are created
1757 in the @code{Staff} context.
1758 If you wish to place bar numbers, metronome marks or rehearsal
1759 marks in accordance with the value of their
1760 @code{outside-staff-priority} the @code{Bar_number_engraver},
1761 @code{Metronome_mark_engraver} or @code{Mark_engraver} respectively
1762 should be removed from the @code{Score} context and placed in the
1763 top @code{Staff} context. If this is done, these marks will be
1764 given the following default @code{outside-staff-priority} values:
1766 @multitable @columnfractions .3 .3
1767 @headitem Layout Object @tab Priority
1768 @item @code{RehearsalMark} @tab @code{1500}
1769 @item @code{MetronomeMark} @tab @code{1000}
1770 @item @code{BarNumber} @tab @code{ 100}
1773 If the default values of @code{outside-staff-priority} do not
1774 give you the placing you want, the priority of any of the objects
1775 may be overridden. Suppose we would
1776 like the ottava bracket to be placed below the text spanner in the
1777 example above. All we need to do is to look up the priority of
1778 @code{OttavaBracket} in the IR or in the tables above, and reduce
1779 it to a value lower than that of a @code{TextSpanner}, remembering
1780 that @code{OttavaBracket} is created in the @code{Staff} context:
1782 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1783 % Set details for later Text Spanner
1784 \override TextSpanner #'bound-details #'left #'text
1785 = \markup { \small \bold Slower }
1786 % Place dynamics above staff
1788 %Place following Ottava Bracket below Text Spanners
1789 \once \override Staff.OttavaBracket #'outside-staff-priority = #340
1790 % Start Ottava Bracket
1795 % Add Dynamic Line Spanner
1801 c\ff c \stopTextSpan
1802 % Stop Ottava Bracket
1807 Changing the @code{outside-staff-priority} can also be used to
1808 control the vertical placement of individual objects, although
1809 the results may not always be desirable. Suppose we would
1810 like @qq{Text3} to be placed above @qq{Text4} in the example
1811 under Automatic behaviour, above (see @ref{Automatic behaviour}).
1812 All we need to do is to look up the priority of @code{TextScript}
1813 in the IR or in the tables above, and increase the priority of
1814 @qq{Text3} to a higher value:
1816 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1819 \once \override TextScript #'outside-staff-priority = #500
1824 This certainly lifts @qq{Text3} above @qq{Text4} but it also
1825 lifts it above @qq{Text2}, and @qq{Text4} now drops down.
1826 Perhaps this is not so good. What we would really like to do
1827 is to position all the annotation at the same distance above
1828 the staff? To do this, we clearly
1829 will need to space the notes out horizontally to make more
1830 room for the text. This is done using the @code{textLengthOn}
1833 @subheading \textLengthOn
1835 @funindex \textLengthOn
1836 @cindex notes, spreading out with text
1838 By default, text produced by markup takes up no horizontal space
1839 as far as laying out the music is concerned. The @code{\textLengthOn}
1840 command reverses this behaviour, causing the notes to be spaced
1841 out as far as is necessary to accommodate the text:
1843 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1844 \textLengthOn % Cause notes to space out to accommodate text
1851 The command to revert to the default behaviour is
1852 @code{\textLengthOff}. Remember @code{\once} only works with
1853 @code{\override}, @code{\set}, @code{\revert} or @code{unset},
1854 so cannot be used with @code{\textLengthOn}.
1856 Markup text will also avoid notes which project above the staff.
1857 If this is not desired, the automatic displacement upwards may
1858 be turned off by setting the priority to @code{#f}. Here's an
1859 example to show how markup text interacts with such notes.
1861 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1862 % This markup is short enough to fit without collision
1866 % This is too long to fit, so it is displaced upwards
1870 % Turn off collision avoidance
1871 \once \override TextScript #'outside-staff-priority = ##f
1875 % Turn off collision avoidance
1876 \once \override TextScript #'outside-staff-priority = ##f
1877 \textLengthOn % and turn on textLengthOn
1878 c,,2^"Long Text " % Spaces at end are honoured
1883 @subheading Dynamics
1885 Dynamic markings will normally be positioned beneath the
1886 staff, but may be positioned above with the @code{dynamicUp}
1887 command. They will be positioned vertically relative to the
1888 note to which they are attached, and will float below (or above)
1889 all within-staff objects such as phrasing slurs and bar numbers.
1890 This can give quite acceptable results, as this example
1893 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1898 bes4.~\f\< \( bes4 bes8 des4\ff\> c16 bes\! |
1899 ees,2.~\)\mf ees4 r8 |
1902 However, if the notes and attached dynamics are close
1903 together the automatic placement will avoid collisions
1904 by displacing later dynamic markings further away, but this may
1905 not be the optimum placement, as this rather artificial example
1908 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1914 Should a similar situation arise in @q{real} music, it may
1915 be preferable to space out the notes
1916 a little further, so the dynamic markings can all fit at the
1917 same vertical distance from the staff. We were able to do this
1918 for markup text by using the @code{\textLengthOn} command, but there
1919 is no equivalent command for dynamic marks. So we shall have to
1920 work out how to do this using @code{\override} commands.
1922 @subheading Grob sizing
1925 @cindex sizing grobs
1926 @cindex @code{X-offset}
1927 @cindex @code{Y-offset}
1928 @cindex @code{X-extent}
1929 @cindex @code{Y-extent}
1931 First we must learn how grobs are sized. All grobs have a
1932 reference point defined within them which is used to position
1933 them relative to their parent object. This point in the grob
1934 is then positioned at a horizontal distance, @code{X-offset},
1935 and at a vertical distance, @code{Y-offset}, from its parent.
1936 The horizontal extent of the object is given by a pair of
1937 numbers, @code{X-extent}, which say where the left and right
1938 edges are relative to the reference point. The vertical extent
1939 is similarly defined by a pair of numbers, @code{Y-extent}.
1940 These are properties of all grobs which support the
1941 @code{grob-interface}.
1943 @cindex @code{extra-spacing-width}
1945 By default, outside-staff objects are given a width of zero so
1946 that they may overlap in the horizontal direction. This is done
1947 by the trick of adding infinity to the leftmost extent and
1948 minus infinity to the rightmost extent by setting the
1949 @code{extra-spacing-width} to @code{'(+inf.0 . -inf.0)}. So
1950 to ensure they do not overlap in the horizontal direction we
1951 must override this value of @code{extra-spacing-width} to
1952 @code{'(0 . 0)} so the true width shines through. This is
1953 the command to do this for dynamic text:
1956 \override DynamicText #'extra-spacing-width = #'(0 . 0)
1960 Let's see if this works in our previous example:
1962 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1964 \override DynamicText #'extra-spacing-width = #'(0 . 0)
1969 Well, it has certainly stopped the dynamic marks being
1970 displaced, but two problems remain. The marks should be
1971 spaced a little further apart and it would be better
1972 if they were all the same distance from the staff.
1973 We can solve the first problem easily. Instead of making
1974 the @code{extra-spacing-width} zero we could add a little
1975 more to it. The units are the space between two staff
1976 lines, so moving the left edge half a unit to the left and the
1977 right edge half a unit to the right should do it:
1979 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1981 % Extend width by 1 staff space
1982 \override DynamicText #'extra-spacing-width = #'(-0.5 . 0.5)
1987 This looks better, but maybe we would prefer the dynamic marks
1988 to be aligned along the same baseline rather than going up and
1989 down with the notes. The property to do this is
1990 @code{staff-padding} which is covered in the following section.
1993 @node Collisions of objects
1994 @section Collisions of objects
1998 * Fixing overlapping notation::
1999 * Real music example::
2002 @node Moving objects
2003 @subsection Moving objects
2005 This may come as a surprise, but LilyPond is not perfect. Some
2006 notation elements can overlap. This is unfortunate, but in fact
2007 rather rare. Usually the need to move objects is for clarity or
2008 aesthetic reasons -- they would look better with a little more
2009 or a little less space around them.
2011 There are three main main approaches to resolving overlapping
2012 notation. They should be considered in the following order:
2016 The @strong{direction} of one of the overlapping objects may
2017 be changed using the predefined commands listed above for
2018 within-staff objects (see @ref{Within-staff objects}).
2019 Stems, slurs, beams, ties, dynamics, text and tuplets may be
2020 repositioned easily in this way. The limitation is that you
2021 have a choice of only two positions, and neither may be
2025 The @strong{object properties}, which LilyPond uses
2026 when positioning layout objects, may be modified using
2027 @code{\override}. The advantages
2028 of making changes to this type of property are (a) that some
2029 other objects will be moved automatically if necessary to make
2030 room and (b) the single override can apply to all instances of
2031 the same type of object. Such properties include:
2037 This has already been covered in some detail -- see
2038 @ref{Within-staff objects}.
2041 @code{padding}, @code{left-padding},
2042 @code{right-padding}, @code{staff-padding}
2044 @cindex left-padding property
2045 @cindex padding property
2046 @cindex right-padding property
2047 @cindex staff-padding property
2048 As an object is being positioned the value of its @code{padding}
2049 property specifies the gap that must be left between itself and
2050 the nearest edge of the object against which it is being
2051 positioned. Note that it is the @code{padding} value of the object
2052 @strong{being placed} that is used;
2053 the @code{padding} value of the object which is already placed is
2054 ignored. Gaps specified by @code{padding} can be applied
2055 to all objects which support the @code{side-position-interface}.
2057 Instead of @code{padding}, the placement of groups of accidentals
2058 is controlled by @code{left-padding} and @code{right-padding}.
2059 These properties are to be found in the @code{AccidentalPlacement}
2060 object which, note, lives in the @strong{staff} context. Because
2061 accidentals are always positioned after and to the left of
2062 note heads only the @code{right-padding} property has any effect.
2064 The @code{staff-padding} property is closely related to the
2065 @code{padding} property: @code{padding}
2066 controls the minimum amount of space between any object which
2067 supports the @code{side-position-interface} and the nearest
2068 other object (generally the note or the staff lines);
2069 @code{staff-padding} applies only to those objects which are always
2070 set outside the staff -- it controls the minimum amount of space
2071 that should be inserted between that object and the staff. Note
2072 that @code{staff-padding} has no effect on objects which are
2073 positioned relative to the note rather than the staff, even though
2074 it may be overridden without error for such objects -- it is simply
2077 To discover which padding property is required for the object
2078 you wish to reposition, you
2079 need to return to the IR and look up the object's properties.
2080 Be aware that the padding properties might not be located in the
2081 obvious object, so look in objects that appear to be related.
2083 All padding values are measured in staff spaces. For most
2084 objects, this value is set by default to be around 1.0 or less
2085 (it varies with each object). It may be overridden if a larger
2086 (or smaller) gap is required.
2089 @code{self-alignment-X}
2091 @cindex self-alignment-X property
2092 This property can be used to align the object to the left, to
2093 the right, or to center it with respect to the parent object's
2094 reference point. It may be used with all objects which support
2095 the @code{self-alignment-interface}. In general these are objects
2096 that contain text. The values are @code{LEFT}, @code{RIGHT}
2097 or @code{CENTER}. Alternatively, a numerical value between
2098 @code{-1} and @code{+1} may be specified, where @code{-1} is
2099 left-aligned, @code{+1} is right-aligned, and numbers in between
2100 move the text progressively from left-aligned to right-aligned.
2101 Numerical values greater than @code{1} may be specified to move
2102 the text even further to the left, or less than @code{-1} to
2103 move the text even further to the right. A change of @code{1}
2104 in the value corresponds to a movement of half the text's length.
2107 @code{extra-spacing-width}
2109 @cindex extra-spacing-width property
2110 This property is available for all objects which support the
2111 @code{item-interface}. It takes two numbers, the first is added
2112 to the leftmost extent and the second is added to the rightmost
2113 extent. Negative numbers move the edge to the left, positive to
2114 the right, so to widen an object the first number must be negative,
2115 the second positive. Note that not all objects honour both
2116 numbers. For example, the @code{Accidental} object only takes
2117 notice of the first (left edge) number.
2120 @code{staff-position}
2122 @cindex staff-position property
2123 @code{staff-position} is a property of the
2124 @code{staff-symbol-referencer-interface}, which is supported by
2125 objects which are positioned relative to the staff. It specifies
2126 the vertical position of the object relative to the center line
2127 of the staff in half staff-spaces. It is useful in resolving
2128 collisions between layout objects like multi-measure rests, ties
2129 and notes in different voices.
2134 @cindex force-hshift property
2136 Closely spaced notes in a chord, or notes occuring at the same
2137 time in different voices, are arranged in two, occasionally more,
2138 columns to prevent the note heads overlapping. These are called
2139 note columns, and an object called @code{NoteColumn} is created
2140 to lay out the notes in that column.
2142 The @code{force-hshift}
2143 property is a property of a @code{NoteColumn} (actually of the
2144 @code{note-column-interface}). Changing it permits a note column
2145 to be moved in units appropriate to a note column, viz. the note
2146 head width of the first voice note. It should be used in
2147 complex situations where the normal @code{\shiftOn} commands (see
2148 @ref{Explicitly instantiating voices}) do
2149 not resolve the note conflict. It is preferable to the
2150 @code{extra-offset} property for this purpose as there is no need
2151 to work out the distance in staff-spaces, and moving the notes
2152 into or out of a @code{NoteColumn} affects other actions such as
2157 Objects do not all have all of these properties in general.
2158 It is necessary to go to the IR to look up which properties
2159 are available for the object in question.
2162 Finally, when all else fails, objects may be manually repositioned
2163 relative to the staff center line verically, or by
2164 displacing them by any distance to a new position. The
2165 disadvantages are that the correct values for the repositioning
2166 have to be worked out, often by trial and error, for every object
2167 individually, and, because the movement is done after LilyPond has
2168 placed all other objects, the user is responsible for avoiding any
2169 collisions that might ensue. But the main difficulty with this
2170 approach is that the repositioning values may need to be reworked
2171 if the music is later modified. The properties that can be used
2172 for this type of manual repositioning are:
2176 @cindex extra-offset property
2177 This property applies to any layout object
2178 supporting the @code{grob-interface}. It takes a pair of
2179 numbers which specify the extra displacement in the horizontal and
2180 vertical directions. Negative numbers move the object to
2181 the left or down. The units are staff-spaces. The extra
2182 displacement is made after the typesetting of objects is
2183 finished, so an object may be repositioned anywhere without
2184 affecting anything else.
2187 @cindex positions property
2188 This is most useful for manually adjusting the slope and height
2189 of beams, slurs, and tuplets. It takes a pair of numbers
2190 giving the position of the left and right ends of the beam, slur,
2191 etc. relative to the center line of the staff. Units are
2192 staff-spaces. Note, though, that slurs and phrasing slurs cannot
2193 be repositioned by arbitrarily large amounts. LilyPond first
2194 generates a list of possible positions for the slur and by default
2195 finds the slur that @qq{looks best}. If the @code{positions}
2196 property has been overridden the slur that is closest to the
2197 requested positions is selected from the list.
2200 Objects do not all have all of these properties in general.
2201 It is necessary to go to the IR to look up which properties
2202 are available for the object in question.
2206 Here is a list of the objects which are most likely to be
2207 involved in collisions, together with the name of the object which
2208 should be looked up in the IR in order to discover which properties
2209 should be used to move them.
2211 @multitable @columnfractions .5 .5
2212 @headitem Object type @tab Object name
2213 @item Articulations @tab @code{Script}
2214 @item Beams @tab @code{Beam}
2215 @item Dynamics (vertically) @tab @code{DynamicLineSpanner}
2216 @item Dynamics (horizontally) @tab @code{DynamicText}
2217 @item Fingerings @tab @code{Fingering}
2218 @item Rehearsal / Text marks @tab @code{RehearsalMark}
2219 @item Slurs @tab @code{Slur}
2220 @item Text e.g. @code{^"text"} @tab @code{TextScript}
2221 @item Ties @tab @code{Tie}
2222 @item Tuplets @tab @code{TupletBracket}
2226 @node Fixing overlapping notation
2227 @subsection Fixing overlapping notation
2229 Let's now see how the properties in the previous section can
2230 help to resolve overlapping notation.
2232 @subheading padding property
2233 @cindex padding property
2235 The @code{padding} property can be set to increase
2236 (or decrease) the distance between symbols that are printed
2237 above or below notes.
2239 @lilypond[quote,fragment,relative=1,verbatim]
2241 \override Script #'padding = #3
2245 @lilypond[quote,fragment,relative=1,verbatim]
2246 % This will not work, see below:
2247 \override MetronomeMark #'padding = #3
2251 \override Score.MetronomeMark #'padding = #3
2256 Note in the second example how important it is to figure out what
2257 context handles a certain object. Since the @code{MetronomeMark}
2259 is handled in the @code{Score} context, property changes in the
2260 @code{Voice} context will not be noticed. For more details, see
2261 @ruser{Constructing a tweak}.
2263 If the @code{padding} property of an object is increased when that
2264 object is in a stack of objects being positioned according to
2265 their @code{outside-staff-priority}, then that object and all
2266 objects outside it are moved.
2269 @subheading left-padding and right-padding
2270 @cindex left-padding property
2271 @cindex right-padding property
2273 The @code{right-padding} property affects the spacing between the
2274 accidental and the note to which it applies. It is not often
2275 required, but the following example shows one situation where it
2276 is needed. Suppose we wish to show a chord containing both
2277 a B-natural and a B-flat. To avoid ambiguity we would like to
2278 precede the notes with both a natural and a flat sign. Here
2279 are a few attempts to do this:
2281 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2287 None work, with the second two showing bad collisions between
2290 One way of achieving this is to override the accidental stencil
2291 with a markup containing the natural and flat symbols in the
2292 order we would like, like this:
2294 @lilypond[quote,ragged-right,verbatim]
2295 naturalplusflat = \markup { \natural \flat }
2297 \once \override Accidental
2298 #'stencil = #ly:text-interface::print
2299 \once \override Accidental #'text = #naturalplusflat
2300 \once \override Score.AccidentalPlacement #'right-padding = #1.5
2306 This necessarily uses an override for the accidental stencil which
2307 will not be covered until later. The stencil type must be a
2308 procedure, here changed to print the contents of the @code{text}
2309 property of @code{Accidental}, which itself is set to be a natural
2310 sign followed by a flat sign. These are then moved further away
2311 from the note head by overriding @code{right-padding}.
2315 @subheading staff-padding property
2316 @cindex staff-padding property
2318 @code{staff-padding} can be used to align objects such as dynamics
2319 along a baseline at a fixed height above the staff, rather than
2320 at a height dependent on the position of the note to which they
2321 are attached. It is not a property of
2322 @code{DynamicText} but of @code{DynamicLineSpanner}.
2323 This is because the baseline should apply equally to @strong{all}
2324 dynamics, including those created as extended spanners.
2325 So this is the way to align the dynamic marks in the example
2326 taken from the previous section:
2328 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2330 % Extend width by 1 unit
2331 \override DynamicText #'extra-spacing-width = #'(-0.5 . 0.5)
2332 % Align dynamics to a base line 2 units above staff
2333 \override DynamicLineSpanner #'staff-padding = #2
2338 @subheading self-alignment-X property
2339 @cindex self-alignment-X property
2341 The following example shows how this can resolve the collision
2342 of a string fingering object with a note's stem by aligning the
2343 right edge with the reference point of the parent note:
2345 @lilypond[quote,fragment,ragged-right,verbatim,relative=3]
2348 \once \override StringNumber #'self-alignment-X = #RIGHT
2352 @subheading staff-position property
2353 @cindex staff-position property
2355 Multimeasure rests in one voice can collide with notes in another.
2356 Since these rests are typeset centered between the bar lines, it
2357 would require significant effort for LilyPond to figure out which
2358 other notes might collide with it, since all the current collision
2359 handling between notes and between notes and rests is done only
2360 for notes and rests that occur at the same time. Here's an
2361 example of a collision of this type:
2363 @lilypond[quote,verbatim,fragment,ragged-right, relative=1]
2364 << {c c c c} \\ {R1} >>
2367 The best solution here is to move the multimeasure rest down,
2368 since the rest is in voice two.
2369 The default in @code{\voiceTwo} (i.e. in the second voice of a
2370 @code{<<@{...@} \\ @{...@}>>} construct)
2371 is that @code{staff-position} is set to -4 for MultiMeasureRest,
2372 so we need to move it, say, four half-staff spaces down to
2375 @lilypond[quote,verbatim,fragment,ragged-right, relative=1]
2379 \override MultiMeasureRest #'staff-position = #-8
2384 This is better than using, for example, @code{extra-offset},
2385 because the ledger line above the rest is inserted automatically.
2387 @subheading extra-offset property
2388 @cindex extra-offset property
2390 The @code{extra-offset} property provides complete control over the
2391 positioning of an object both horizontally and vertically.
2393 In the following example, the second fingering is moved a little to
2394 the left, and 1.8 staff space downwards:
2396 @lilypond[quote,fragment,relative=1,verbatim]
2399 \once \override Fingering
2400 #'extra-offset = #'(-0.3 . -1.8)
2405 @subheading positions property
2406 @cindex positions property
2408 The @code{positions} property allows the position and slope of
2409 tuplets, slurs, phrasing slurs and beams to be controlled
2410 manually. Here's an example which has an ugly phrasing slur
2411 due to its trying to avoid the slur on the acciaccatura.
2413 @lilypond[quote,verbatim,fragment,ragged-right,relative=1]
2414 r4 \acciaccatura e8\( d8 c ~c d c d\)
2418 We could simply move the phrasing slur above the notes, and this
2419 would be the preferred solution:
2421 @lilypond[quote,verbatim,fragment,ragged-right,relative=1]
2424 \acciaccatura e8\( d8 c ~c d c d\)
2428 but if there were some reason why this could not be done the
2429 other alternative would be to move the left end of the phrasing
2430 slur down a little using the @code{positions} property. This
2431 also resolves the rather nasty shape.
2433 @lilypond[quote,verbatim,fragment,ragged-right,relative=1]
2435 \once \override PhrasingSlur #'positions = #'(-4 . -3)
2437 e8\( d8 c ~c d c d\)
2440 Here's a further example taken from the opening of the left-hand
2441 staff of Chopin's Prelude Op 28 No. 2. We see that the beam
2442 collides with the upper notes:
2444 @lilypond[quote,verbatim,fragment,ragged-right]
2447 << {b,8 ais, b, g,} \\ {e, g e, g} >>
2448 << {b,8 ais, b, g,} \\ {e, g e, g} >>
2453 This can be resolved by manually moving both ends of the beam
2454 up from their position at 2 staff-spaces above the center line to,
2457 @lilypond[quote,verbatim,fragment,ragged-right]
2461 \override Beam #'positions = #'(3 . 3)
2466 << {b,8 ais, b, g,} \\ {e, g e, g} >>
2471 Note that the override continues to apply in the first voice of
2472 the second block of quavers, but not to any of the beams in the
2475 @subheading force-hshift property
2476 @cindex force-hshift property
2477 @c FIXME: formatting stuff (ie not important right now IMO)
2478 @c @a nchor Chopin finally corrected TODOgp
2480 We can now see how to apply the final corrections to the Chopin
2481 example introduced at the end of @ref{I'm hearing Voices}, which
2482 was left looking like this:
2484 @lilypond[quote,verbatim,fragment,ragged-right]
2485 \new Staff \relative c'' {
2488 { c2 aes4. bes8 } \\
2500 The lower two notes of the first chord (i.e,
2501 those in the third voice) should not be shifted away from the
2502 note column of the higher two notes. To correct this we set
2503 @code{force-hshift}, which is a property of
2504 @code{NoteColumn}, of these notes to zero.
2505 The lower note of the second chord is best placed just to the
2506 right of the higher notes. We achieve this by setting
2507 @code{force-hshift} of this note to 0.5, ie half a note head's
2508 width to the right of the note column of the higher notes.
2510 Here's the final result:
2512 @lilypond[quote,verbatim,fragment,ragged-right]
2513 \new Staff \relative c'' {
2516 { c2 aes4. bes8 } \\
2519 \once \override NoteColumn #'force-hshift = #0 <ees c>2
2520 \once \override NoteColumn #'force-hshift = #0.5 des2
2528 @node Real music example
2529 @subsection Real music example
2531 We end this section on Tweaks by showing the steps to be taken to
2532 deal with a tricky example which needs several tweaks to produce
2533 the desired output. The example has been deliberately chosen to
2534 illustrate the use of the Notation Reference to resolve unusual
2535 problems with notation. It is not representative of more usual
2536 engraving process, so please do not let these difficulties put
2537 you off! Fortunately, difficulties like these are not very common!
2539 The example is from Chopin's Première Ballade, Op. 23, bars 6 to
2540 9, the transition from the opening Lento to Moderato.
2541 Here, first, is what we want the output to look like, but to avoid
2542 over-complicating the example too much we have left out the
2543 dynamics, fingering and pedalling.
2545 @c The following should appear as music without code
2546 @lilypond[quote,ragged-right]
2547 rhMusic = \relative c'' {
2550 \once \override Tie #'staff-position = #3.5
2554 \override Staff.NoteCollision #'merge-differently-headed = ##t
2555 \override Staff.NoteCollision #'merge-differently-dotted = ##t
2556 bes2.^\markup {\bold "Moderato"} r8
2558 {c,8[ d fis bes a] | }
2560 % Reposition the c2 to the right of the merged note
2561 {c,8~ \once \override NoteColumn #'force-hshift = #1.0
2562 % Move the c2 out of the main note column so the merge will work
2565 % Stem on the d2 must be down to permit merging
2566 {s8 \stemDown \once \override Stem #'transparent = ##t d2}
2570 \revert Staff.NoteCollision #'merge-differently-headed
2571 \revert Staff.NoteCollision #'merge-differently-dotted
2575 lhMusic = \relative c' {
2577 <d g, d>1)\arpeggio |
2584 \new Staff = "RH" <<
2588 \new Staff = "LH" <<
2597 We note first that the right hand part in the third bar
2598 requires four voices. These are the five beamed eighth notes,
2599 the tied C, the half-note D which is merged with the eighth note
2600 D, and the dotted quarter note F-sharp, which is also merged with
2601 the eighth note at the same pitch. Everything else is in a single
2602 voice, so the easiest way is to introduce these four voices
2603 temporarily at the time they are needed. If you have forgotten
2604 how to do this, look at @ref{I'm hearing Voices}. Let us begin
2605 by entering the notes as two variables and setting up the staff
2606 structure in a score block, and see what LilyPond produces by
2609 @lilypond[quote,verbatim,ragged-right]
2610 rhMusic = \relative c'' {
2615 % Start polyphonic section of four voices
2617 {c,8 d fis bes a | }
2628 lhMusic = \relative c' {
2637 \new Staff = "RH" <<
2641 \new Staff = "LH" <<
2650 All the notes are right, but the appearance is far from
2651 satisfactory. The tie clashes with the change in time signature,
2652 the beaming in the third bar is wrong, the notes are not
2653 merged together, and several notation elements are missing.
2654 Let's first deal with the easier things.
2655 We can correct the beaming by inserting a beam
2656 manually, and we can easily add the left hand slur and the right
2657 hand phrasing slur, since these were all covered in the Tutorial.
2660 @lilypond[quote,verbatim,ragged-right]
2661 rhMusic = \relative c'' {
2666 % Start polyphonic section of four voices
2668 {c,8[ d fis bes a] | }
2679 lhMusic = \relative c' {
2688 \new Staff = "RH" <<
2692 \new Staff = "LH" <<
2701 The first bar is now correct. The second bar contains an arpeggio
2702 and is terminated by a double bar line. How do we do these, as they
2703 have not been mentioned in this Learning Manual? This is where
2704 we need to turn to the Notation Reference. Looking up @q{arpeggio}
2705 and @q{bar line} in the
2706 index quickly shows us that an arpeggio is produced by appending
2707 @code{\arpeggio} to a chord, and a double bar line is produced by
2708 the @code{\bar "||"} command. That's easily done. We next need
2709 to correct the collision of the tie with the time signature. This
2710 is best done by moving the tie upwards. Moving objects was covered
2711 earlier in @ref{Moving objects}, which says that objects positioned
2712 relative to the staff can be moved by overriding their
2713 @code{staff-position} property, which is specified in half staff
2714 spaces relative to the center line of the staff. So the following
2715 override placed just before the first tied note would move the tie
2716 up to 3.5 half staff spaces above the center line:
2718 @code{\once \override Tie #'staff-position = #3.5}
2720 This completes bar two, giving:
2722 @lilypond[quote,verbatim,ragged-right]
2723 rhMusic = \relative c'' {
2725 \once \override Tie #'staff-position = #3.5
2730 % Start polyphonic section of four voices
2732 {c,8[ d fis bes a] | }
2743 lhMusic = \relative c' {
2745 <d g, d>1)\arpeggio |
2752 \new Staff = "RH" <<
2756 \new Staff = "LH" <<
2765 On to bar three and the start of the Moderato section. The
2766 tutorial showed how to add embolded text with the
2767 @code{\markup} command, so adding @q{Moderato} in bold is easy.
2768 But how do we merge notes in different voices together? The
2769 index in the Notation Reference does not mention merging,
2770 but a search of the text for @q{merge} quickly leads us to
2771 the overrides for merging differently headed and differently
2772 dotted notes in @ruser{Collision Resolution}. In our
2773 example we need to merge both types of note for the duration
2774 of the polyphonic section in bar 3, so using the information
2775 in the Notation Reference we add
2778 \override Staff.NoteCollision #'merge-differently-headed = ##t
2779 \override Staff.NoteCollision #'merge-differently-dotted = ##t
2783 to the start of that section and
2786 \revert Staff.NoteCollision #'merge-differently-headed
2787 \revert Staff.NoteCollision #'merge-differently-dotted
2793 @lilypond[quote,verbatim,ragged-right]
2794 rhMusic = \relative c'' {
2796 \once \override Tie #'staff-position = #3.5
2800 bes2.^\markup {\bold "Moderato"} r8
2801 \override Staff.NoteCollision #'merge-differently-headed = ##t
2802 \override Staff.NoteCollision #'merge-differently-dotted = ##t
2803 % Start polyphonic section of four voices
2805 {c,8[ d fis bes a] | }
2813 \revert Staff.NoteCollision #'merge-differently-headed
2814 \revert Staff.NoteCollision #'merge-differently-dotted
2818 lhMusic = \relative c' {
2820 <d g, d>1)\arpeggio |
2827 \new Staff = "RH" <<
2831 \new Staff = "LH" <<
2840 These overrides have merged the two F-sharp notes, but not the two
2841 on D. Why not? The answer is there in the same section in the
2842 Notation Reference -- notes being merged must have stems in
2843 opposite directions and two notes cannot be merged successfully if
2844 there is a third note in the same note column. Here the two D's
2845 both have upward stems and there is a third note -- the C. We know
2846 how to change the stem direction using @code{\stemDown}, and
2847 the Notation Reference also says how to move the C -- apply a shift
2848 using one of the @code{\shift} commands. But which one?
2849 The C is in voice two which has shift off, and the two D's are in
2850 voices one and three, which have shift off and shift on,
2851 respectively. So we have to shift the C a further level still
2852 using @code{\shiftOnn} to avoid it interferring with the two D's.
2853 Applying these changes gives:
2855 @lilypond[quote,verbatim,ragged-right]
2856 rhMusic = \relative c'' {
2858 \once \override Tie #'staff-position = #3.5
2862 bes2.^\markup {\bold "Moderato"} r8
2863 \override Staff.NoteCollision #'merge-differently-headed = ##t
2864 \override Staff.NoteCollision #'merge-differently-dotted = ##t
2865 % Start polyphonic section of four voices
2867 {c,8[ d fis bes a] | }
2869 % Move the c2 out of the main note column so the merge will work
2870 {c,8~ \shiftOnn c2 | }
2872 % Stem on the d2 must be down to permit merging
2873 {s8 \stemDown d2 | }
2877 \revert Staff.NoteCollision #'merge-differently-headed
2878 \revert Staff.NoteCollision #'merge-differently-dotted
2882 lhMusic = \relative c' {
2884 <d g, d>1)\arpeggio |
2891 \new Staff = "RH" <<
2895 \new Staff = "LH" <<
2904 Nearly there. Only two problems remain: The downward stem on the
2905 merged D should not be there, and the C would be better positioned
2906 to the right of the D's. We know how to do both of these from the
2907 earlier tweaks: we make the stem transparent, and move the C with
2908 the @code{force-hshift} property. Here's the final result:
2910 @lilypond[quote,verbatim,ragged-right]
2911 rhMusic = \relative c'' {
2914 \once \override Tie #'staff-position = #3.5
2918 bes2.^\markup {\bold "Moderato"} r8
2919 \override Staff.NoteCollision #'merge-differently-headed = ##t
2920 \override Staff.NoteCollision #'merge-differently-dotted = ##t
2922 {c,8[ d fis bes a] | }
2924 % Reposition the c2 to the right of the merged note
2925 {c,8~ \once \override NoteColumn #'force-hshift = #1.0
2926 % Move the c2 out of the main note column so the merge will work
2929 % Stem on the d2 must be down to permit merging
2930 {s8 \stemDown \once \override Stem #'transparent = ##t d2}
2934 \revert Staff.NoteCollision #'merge-differently-headed
2935 \revert Staff.NoteCollision #'merge-differently-dotted
2939 lhMusic = \relative c' {
2941 <d g, d>1)\arpeggio |
2948 \new Staff = "RH" <<
2952 \new Staff = "LH" <<
2962 @node Further tweaking
2963 @section Further tweaking
2966 * Other uses for tweaks::
2967 * Using variables for tweaks::
2968 * Other sources of information::
2969 * Avoiding tweaks with slower processing::
2970 * Advanced tweaks with Scheme::
2973 @node Other uses for tweaks
2974 @subsection Other uses for tweaks
2978 @cindex transparent property, use of
2979 @cindex objects, making invisible
2980 @cindex removing objects
2981 @cindex objects, removing
2982 @cindex hiding objects
2983 @cindex invisible objects
2984 @cindex tying notes across voices
2987 @subheading Tying notes across voices
2989 The following example demonstrates how to connect notes in
2990 different voices using ties. Normally, only two notes in the
2991 same voice can be connected with ties. By using two voices,
2992 with the tied notes in one of them
2994 @lilypond[quote,fragment,relative=2]
2995 << { b8~ b8\noBeam }
3001 and blanking the first up-stem in that voice, the tie appears to
3004 @lilypond[quote,fragment,relative=2,verbatim]
3007 \once \override Stem #'transparent = ##t
3015 To make sure that the just-blanked stem doesn't squeeze the tie
3016 too much, we can lengthen the stem by setting the
3017 @code{length} to @code{8},
3019 @lilypond[quote,fragment,relative=2,verbatim]
3022 \once \override Stem #'transparent = ##t
3023 \once \override Stem #'length = #8
3032 @subheading Simulating a fermata
3034 @cindex stencil property, use of
3035 @cindex fermata, implementing in MIDI
3037 For outside-staff objects it is usually better to override the
3038 object's @code{stencil} property rather than its @code{transparent}
3039 property when you wish to remove it from the printed output.
3040 Setting the @code{stencil} property of an object to @code{#f} will
3041 remove that object entirely from the printed output. This means it
3042 has no effect on the placement of other objects placed relative to
3045 For example, if we wished to change the metronome setting in order
3046 to simulate a fermata in the MIDI output we would not want the
3047 metronome markings to appear in the printed output, and we would
3048 not want it to influence the spacing between the two systems or
3049 the spacing of the notes on the staff. So setting its
3050 @code{stencil} property to @code{#f} would be the best way.
3051 We show here the effect of the two methods:
3053 @lilypond[quote,verbatim,ragged-right]
3056 % Visible tempo marking
3059 \once \override Score.MetronomeMark #'transparent = ##t
3060 % Invisible tempo marking to lengthen fermata note in MIDI
3063 \once \override Score.MetronomeMark #'stencil = ##f
3064 % Invisible tempo marking to restore tempo in MIDI
3074 Both methods remove the metronome mark from the printed output,
3075 and both affect the MIDI timing as required, but the first
3076 (transparent) metronome mark still influences the note spacing
3077 while the second (with no stencil) does not.
3081 @node Using variables for tweaks
3082 @subsection Using variables for tweaks
3084 Override commands are often long and tedious to type, and they
3085 have to be absolutely correct. If the same overrides are to be
3086 used many times it may be worth defining variables to hold them.
3087 Suppose we wish to emphasize certain words in lyrics by printing
3088 them in bold italics. The @code{\italic} and @code{\bold}
3089 commands do not work within lyrics so we must instead use the
3090 following @code{\override} and @code{\revert} commands:
3093 @code{\override Lyrics . LyricText #'font-shape = #'italic}
3094 @code{\override Lyrics . LyricText #'font-series = #'bold}
3096 @code{\revert Lyrics . LyricText #'font-shape}
3097 @code{\revert Lyrics . LyricText #'font-series}
3100 These would be extremely tedious to enter if there were many words
3101 requiring emphasis. So instead we define these as two variables,
3102 and use them as follows:
3104 @lilypond[quote,verbatim]
3106 \override Lyrics . LyricText #'font-shape = #'italic
3107 \override Lyrics . LyricText #'font-series = #'bold
3110 \revert Lyrics . LyricText #'font-shape
3111 \revert Lyrics . LyricText #'font-series
3114 global = { \time 4/4 \partial 4 \key c \major}
3115 SopMusic = \relative c' { c4 | e4. e8 g4 g | a a g }
3116 AltoMusic = \relative c' { c4 | c4. c8 e4 e | f f e }
3117 TenorMusic = \relative c { e4 | g4. g8 c4. b8 | a8 b c d e4 }
3118 BassMusic = \relative c { c4 | c4. c8 c4 c | f8 g a b c4 }
3119 VerseOne = \lyrics { E -- | ter -- nal \emph Fa -- ther, \norm | strong to save, }
3120 VerseTwo = \lyricmode { O | \emph Christ, \norm whose voice the | wa -- ters heard, }
3121 VerseThree = \lyricmode { O | \emph Ho -- ly Spi -- rit, \norm | who didst brood }
3122 VerseFour = \lyricmode { O | \emph Tri -- ni -- ty \norm of | love and pow'r }
3128 \new Voice = "Sop" { \voiceOne \global \SopMusic }
3129 \new Voice = "Alto" { \voiceTwo \AltoMusic }
3130 \new Lyrics \lyricsto "Sop" { \VerseOne }
3131 \new Lyrics \lyricsto "Sop" { \VerseTwo }
3132 \new Lyrics \lyricsto "Sop" { \VerseThree }
3133 \new Lyrics \lyricsto "Sop" { \VerseFour }
3137 \new Voice = "Tenor" { \voiceOne \TenorMusic }
3138 \new Voice = "Bass" { \voiceTwo \BassMusic }
3146 @node Other sources of information
3147 @subsection Other sources of information
3149 The Internals Reference documentation contains a lot of information
3150 about LilyPond, but even more information can be gathered by
3151 looking at the internal LilyPond files. To explore these, first
3152 find the directory appropriate to your system, as follows:
3157 @file{@var{installdir}/lilypond/usr/share/lilypond/current/}
3162 @file{@var{installdir}/LilyPond.app/Contents/Resources/share/lilypond/current/}
3163 by either @code{cd}-ing into this directory from the
3164 Terminal, or control-clicking on the LilyPond application and
3165 selecting @q{Show Package Contents}.
3169 Using Windows Explorer, navigate to
3170 @file{@var{installdir}/LilyPond/usr/share/lilypond/current/}
3172 Within this directory the two interesting subdirectories are
3175 @item @file{../ly/ } - contains files in LilyPond format
3176 @item @file{../scm/} - contains files in Scheme format
3179 Let's begin by looking at some files in @file{../ly/}.
3180 Open @file{../ly/property-init.ly} in a text editor. The one
3181 you normally use for @code{.ly} files will be fine. This file
3182 contains the definitions of all the standard LilyPond built-in
3183 commands, such as @code{\stemUp} and @code{\slurDotted}. You will
3184 see that these are nothing more than definitions of variables
3185 containing one or a group of @code{\override} commands. For
3186 example, @code{/tieDotted} is defined to be:
3190 \override Tie #'dash-period = #0.75
3191 \override Tie #'dash-fraction = #0.1
3195 If you do not like the default values these built-in commands can
3196 be redefined easily, just like any other variable, at the
3197 head of your input file.
3199 The following are the most useful files to be found in
3202 @multitable @columnfractions .4 .6
3205 @item @file{../ly/engraver-init.ly}
3206 @tab Definitions of engraver Contexts
3207 @item @file{../ly/paper-defaults.ly}
3208 @tab Specifications of paper-related defaults
3209 @item @file{../ly/performer-init.ly}
3210 @tab Definitions of performer Contexts
3211 @item @file{../ly/property-init.ly}
3212 @tab Definitions of all common built-in commands
3215 Other settings (such as the definitions of markup commands) are
3216 stored as @code{.scm} (Scheme) files. The Scheme programming
3217 language is used to provide a programmable interface into
3218 LilyPond internal operation. Further explanation of these files
3219 is currently outside the scope of this manual, as a knowledge of
3220 the Scheme language is required. Users should be warned that
3221 a substantial amount of technical knowledge or time is required
3222 to understand Scheme and these files (see @ref{Scheme tutorial}).
3224 If you have this knowledge, the Scheme files which may be of
3227 @multitable @columnfractions .4 .6
3230 @item @file{../scm/auto-beam.scm}
3231 @tab Sub-beaming defaults
3232 @item @file{../scm/define-grobs.scm}
3233 @tab Default settings for grob properties
3234 @item @file{../scm/define-markup-commands.scm}
3235 @tab Specify all markup commands
3236 @item @file{../scm/midi.scm}
3237 @tab Default settings for MIDI output
3238 @item @file{../scm/output-lib.scm}
3239 @tab Settings that affect appearance of frets, colors,
3240 accidentals, bar lines, etc
3241 @item @file{../scm/parser-clef.scm}
3242 @tab Definitions of supported clefs
3243 @item @file{../scm/script.scm}
3244 @tab Default settings for articulations
3249 @node Avoiding tweaks with slower processing
3250 @subsection Avoiding tweaks with slower processing
3252 LilyPond can perform extra checks while it processes files. These
3253 checks will take extra time to perform, but fewer manual tweaks
3254 may be required to obtain an acceptable result. If a text script
3255 or part of the lyrics extends over the margins these checks will
3256 compress that line of the score just enough to fit within the
3259 To be effective under all circumstances these checks must be enabled
3260 by placing the overrides in a Score @code{\with} block, rather than
3261 in-line in music, as follows:
3265 % Makes sure text scripts and lyrics are within the paper margins
3266 \override PaperColumn #'keep-inside-line = ##t
3267 \override NonMusicalPaperColumn #'keep-inside-line = ##t
3273 @node Advanced tweaks with Scheme
3274 @subsection Advanced tweaks with Scheme
3276 Although many things are possible with the @code{\override} and
3277 @code{\tweak} commands, an even more powerful way of modifying
3278 the action of LilyPond is available through a programmable
3279 interface to the LilyPond internal operation. Code written in
3280 the Scheme programming language can be incorporated directly in
3281 the internal operation of LilyPond. Of course, at least a basic
3282 knowledge of programming in Scheme is required to do this, and an
3283 introduction is provided in the @ref{Scheme tutorial}.
3285 As an illustration of one of the many possibilities, instead of
3286 setting a property to a constant it can be set to a Scheme
3287 procedure which is then called whenever that property is accessed
3288 by LilyPond. The property can then be set dynamically to a value
3289 determined by the procedure at the time it is called. In this
3290 example we color the note head in accordance with its position on
3293 @lilypond[quote,verbatim,ragged-right]
3294 #(define (color-notehead grob)
3295 "Color the notehead according to its position on the staff."
3296 (let ((mod-position (modulo (ly:grob-property grob 'staff-position) 7)))
3298 ;; Return rainbow colors
3299 ((1) (x11-color 'red )) ; for C
3300 ((2) (x11-color 'orange )) ; for D
3301 ((3) (x11-color 'yellow )) ; for E
3302 ((4) (x11-color 'green )) ; for F
3303 ((5) (x11-color 'blue )) ; for G
3304 ((6) (x11-color 'purple )) ; for A
3305 ((0) (x11-color 'violet )) ; for B
3311 % Arrange to obtain color from color-notehead procedure
3312 \override NoteHead #'color = #color-notehead
3319 Some -- where o -- ver the Rain -- bow way up high,
3323 Further examples showing the use of these programmable interfaces
3324 can be found in @ref{Tweaking with Scheme}.