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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 one 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} #'@emph{layout_property} = #@emph{value}
190 This will set the property with the name @emph{layout_property}
191 of the layout object with the name
192 @emph{layout_object}, which is a member of the @emph{context}
193 context, to the value @emph{value}.
195 The @emph{context} can be omitted (and usually is) when the
196 required context is unambiguously implied and is one of lowest
197 level contexts, i.e., @code{Voice}, @code{ChordNames} or
198 @code{Lyrics}, and we shall omit it in many of the following
199 examples. We shall see later when it must be specified.
201 For now, don't worry about the @code{#'}, which must precede the
202 layout property, and the @code{#}, which must precede the value.
203 These must always be present in exactly this form. This is the
204 most common command used in tweaking, and most of the rest of
205 this chapter will be directed to presenting examples of how it is
208 Once overridden, the property retains its new value until it is
209 overridden again or a @code{\revert} command is encountered.
210 The @code{\revert} command has the following syntax and causes
211 the value of the property to revert to its original default
212 value; note, not its previous value if several @code{\override}
213 commands have been issued.
216 \revert @emph{context}.@emph{layout_object} #'@emph{layout_property}
219 Again, just like @emph{context} in the @code{\override} command,
220 @emph{context} is often not needed. It will be omitted
221 in many of the following examples.
223 @strong{\overrideProperty command}
225 @cindex overrideProperty command
226 @funindex \overrideProperty
228 There is another form of the override command,
229 @code{\overrideProperty}, which is occasionally required.
230 We mention it here for completeness, but for details see
231 @ruser{Difficult tweaks}.
232 @c Maybe explain in a later iteration -td
234 @strong{\tweak command}
236 @cindex tweak command
239 The final tweaking command which is available is @code{\tweak}.
240 This should be used to change the properties of objects which
241 occur at the same musical moment, such as the notes within a
242 chord. Using @code{\override} would affect all the notes
243 within a chord, whereas @code{\tweak} affects just the following
244 item in the input stream.
246 Here's an example. Suppose we wish to change the size of the
247 middle note (the E) in a C major chord. Let's first see what
248 @code{\once \override} would do:
250 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
252 \once \override NoteHead #'font-size = #-3
256 We see the override affects @emph{all} the notes in the chord.
257 This is because all the notes of a chord occur at the same
258 @emph{musical moment}, and the action of @code{\once} is to
259 apply the override to all layout objects of the type specified
260 which occur at the same musical moment as the @code{\override}
263 The @code{\tweak} command operates in a different way. It acts
264 on the immediately following item in the input stream. However,
265 it is effective only on objects which are created directly from
266 the input stream, essentially note heads and articulations.
267 (Objects such as stems and accidentals are created later and
268 cannot be tweaked in this way). Furthermore, when it is applied
269 to note heads these must be within a chord, i.e., within single
270 angle brackets, so to tweak a single note the @code{\tweak}
271 command must be placed inside single angle brackets with the
274 So to return to our example, the size of the middle note of
275 a chord would be changed in this way:
277 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
279 <c \tweak #'font-size #-3 e g>4
282 Note that the syntax of @code{\tweak} is different from that
283 of the @code{\override} command. Neither the context nor the
284 layout object should be specified; in fact, it would generate
285 an error to do so. These are both implied by the following
286 item in the input stream. So the general syntax of the
287 @code{\tweak} command is simply:
290 \tweak #'@emph{layout_property} = #@emph{value}
293 A @code{\tweak} command can also be used to modify just one in
294 a series of articulations, as shown here:
296 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
298 -\tweak #'color #red ^Red
299 -\tweak #'color #green _Green
302 Note that the @code{\tweak} command must be preceded by an
303 articulation mark as if it were an articulation itself.
305 You can find more details of the @code{\tweak} command in
306 @ruser{Objects connected to the input}.
309 @node The Internals Reference manual
310 @section The Internals Reference manual
312 @cindex Internals Reference
315 * Properties of layout objects::
316 * Properties found in interfaces::
317 * Types of properties::
320 @node Properties of layout objects
321 @subsection Properties of layout objects
323 @cindex properties of layout objects
324 @cindex properties of grobs
325 @cindex grobs, properties of
326 @cindex layout objects, properties of
328 Suppose you have a slur in a score which, to your mind,
329 appears too thin and you'd like to draw it a little heavier.
330 How do you go about doing this? You know from the statements
331 earlier about the flexibility of LilyPond that such a thing
332 should be possible, and you would probably guess that an
333 @code{\override} command would be needed. But is there a
334 heaviness property for a slur, and if there is, how might it
335 be modified? This is where the Internals Reference manual
336 comes in. It contains all the information you might need to
337 construct this and all other @code{\override} commands.
339 Before we look at the Internals Reference a word of warning.
340 This is a @strong{reference} document, which means there is
341 little or no explanation contained within it: its purpose is
342 to present information precisely and concisely. This
343 means it might look daunting at first sight. Don't worry!
344 The guidance and explanation presented here will enable you
345 to extract the information from the Internals Reference for
346 yourself with just a little practice.
348 @cindex override example
349 @cindex Internals Reference, example of using
351 Let's use a concrete example with a simple fragment of real
354 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
359 g[( e]) e d[( f]) a |
363 The man who feels love's sweet e -- mo -- tion
368 Suppose now that we decide we would like the slurs to be a
369 little heavier. Is this possible? The slur is certainly a
370 layout object, so the question is, @q{Is there a property
371 belonging to a slur which controls the heaviness?} To answer
372 this we must look in the Internals Reference, or IR for short.
374 The IR for the version of LilyPond you are using may be found
375 on the LilyPond website at @uref{http://lilypond.org}. Go to the
376 documentation page and click on the Internals Reference link.
377 For learning purposes you should use the standard html version,
378 not the @q{one big page} or the PDF. For the next few
379 paragraphs to make sense you will need to actually do this
382 Under the heading @strong{Top} you will see five links. Select
383 the link to the @emph{Backend}, which is where information about
384 layout objects is to be found. There, under the heading
385 @strong{Backend}, select the link to @emph{All layout objects}.
386 The page that appears lists all the layout objects used in your
387 version of LilyPond, in alphabetic order. Select the link to
388 Slur, and the properties of Slurs are listed.
390 (An alternative way of finding this page is from the Notation
391 Reference. On one of the pages that deals with slurs you may
392 find a link to the Internals Reference. This link will
393 take you directly to this page, but often it is easier to go
394 straight to the IR and search there.)
396 This Slur page in the IR tells us first that Slur objects are
398 Slur_engraver. Then it lists the standard settings. Note
399 these are @strong{not} in alphabetic order. Browse down
400 them looking for a property that might control the heaviness
401 of slurs, and you should find
404 @code{thickness} (number)
406 Line thickness, generally measured in @code{line-thickness}
409 This looks a good bet to change the heaviness. It tells us that
410 the value of @code{thickness} is a simple @emph{number},
411 that the default value is 1.2, and that the units are
412 in another property called @code{line-thickness}.
414 As we said earlier, there are few to no explanations in the IR,
415 but we already have enough information to try changing the
416 slur thickness. We see that the name of the layout object
417 is @code{Slur}, that the name of the property to change is
418 @code{thickness} and that the new value should be a number
419 somewhat larger than 1.2 if we are to make slurs thicker.
421 We can now construct the @code{\override} command by simply
422 substituting the values we have found for the names, omitting
423 the context. Let's use a very large value for the thickness
424 at first, so we can be sure the command is working. We get:
427 \override Slur #'thickness = #5.0
430 Don't forget the @code{#'} preceding the
431 property name and and @code{#} preceding the new value!
433 The final question is, @q{Where should this command be
434 placed?} While you are unsure and learning, the best
435 answer is, @q{Within the music, before the first slur and
436 close to it.} Let's do that:
438 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
442 % Increase thickness of all following slurs from 1.2 to 5.0
443 \override Slur #'thickness = #5.0
445 g[( e]) e d[( f]) a |
449 The man who feels love's sweet e -- mo -- tion
455 and we see that the slur is indeed heavier.
457 So this is the basic way of constructing @code{\override}
458 commands. There are a few more complications that we
459 shall meet in later sections, but you now know all the
460 essentials required to make up your own -- but you will
461 still need some practice. This is provided in the examples
464 @subheading Finding the context
465 @cindex context, finding
467 But first, what if we had needed to specify the Context?
468 What should it be? We could guess that slurs are in
469 the Voice context, as they are clearly closely associated
470 with individual lines of music, but can we be sure? To
471 find out, go back to the top of the IR page describing the
472 Slur, where it says @q{Slur objects are created by: Slur
473 engraver}. So slurs will be created in whichever context
474 the @code{Slur_engraver} is in. Follow the link to the
475 @code{Slur_engraver} page. At the very bottom it tells
476 us that @code{Slur_engraver} is part of five Voice contexts,
477 including the standard voice context, @code{Voice}, so our
478 guess was correct. And because @code{Voice} is one of the
479 lowest level contexts which is implied unambiguously by
480 the fact that we are entering notes, we can omit it in this
483 @subheading Overriding once only
485 @cindex overriding once only
486 @cindex once override
489 As you can see, @emph{all} the slurs are thicker in the
490 final example above. But what if we
491 wanted just the first slur to be thicker? This is achieved
492 with the @code{\once} command. Placed immediately before
493 the @code{\override} command it causes it to change only the
494 slur which begins on the @strong{immediately following} note.
496 immediately following note does not begin a slur the command
497 has no effect at all -- it is not remembered until a slur
498 is encountered, it is simply discarded. So the command with
500 repositioned as follows:
502 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
507 % Increase thickness of immediately following slur only
508 \once \override Slur #'thickness = #5.0
510 g[( e]) e d[( f]) a |
514 The man who feels love's sweet e -- mo -- tion
520 Now only the first slur is made heavier.
522 The @code{\once} command can also be used before @code{\set}
523 and @code{\unset}, and before the command to be introduced
524 in the following section -- @code{revert}.
526 @subheading Reverting
529 @cindex default properties, reverting
532 Finally, what if we wanted just the first two slurs to be
533 heavier? Well, we could use two commands, each preceded by
534 @code{\once} placed immediately before each of the notes where
537 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
542 % Increase thickness of immediately following slur only
543 \once \override Slur #'thickness = #5.0
545 % Increase thickness of immediately following slur only
546 \once \override Slur #'thickness = #5.0
547 g[( e]) e d[( f]) a |
551 The man who feels love's sweet e -- mo -- tion
557 or we could omit the @code{\once} command and use the
558 @code{\revert} command
559 to return the @code{thickness} property to its default value
560 after the second slur:
562 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
567 % Increase thickness of all following slurs from 1.2 to 5.0
568 \override Slur #'thickness = #5.0
571 % Revert thickness of all following slurs to default of 1.2
572 \revert Slur #'thickness
577 The man who feels love's sweet e -- mo -- tion
583 The @code{\revert} command can be used to return any property
584 changed with @code{\override} back to its default value.
585 You may use whichever method best suits what you want to do.
587 That concludes our introduction to the IR, and the basic
588 method of tweaking. Several examples follow in the later
589 sections of this Chapter, partly to introduce you to some of the
590 additional features of the IR, and partly to give you more
591 practice in extracting information from it. These examples will
592 contain progressively fewer words of guidance and explanation.
594 @node Properties found in interfaces
595 @subsection Properties found in interfaces
597 @cindex interface properties
598 @cindex properties in interfaces
600 Suppose now that we wish to print the lyrics in italics. What
601 form of @code{\override} command do we need to do this?
602 We first look in the IR page listing @q{All layout objects}, as
603 before, and look for an object that might control lyrics. We
604 find @code{LyricText}, which looks right. Clicking on this shows
605 the settable properties for lyric text. These include the
606 @code{font-series} and @code{font-size}, but nothing that might
607 give an italic shape.
608 This is because the shape property is one that is common to all
609 font objects, so, rather than including it in every layout
610 object, it is grouped together with other similar common
611 properties and placed in an @strong{Interface}, the
612 @code{font-interface}.
614 So now we need to learn how to find the properties of interfaces,
615 and to discover what objects use these interface properties.
617 Look again at the IR page which describes LyricText. At the
618 bottom of the page is a list of clickable (in the html versions
619 of the IR) interfaces which LyricText supports. The list has
620 seven items, including @code{font-interface}.
621 Clicking on this brings up the properties associated
622 with this interface, which are also properties of all the objects
623 which support it, including LyricText.
625 Now we see all the user-settable properties which control fonts,
626 including @code{font-shape(symbol)}, where @code{symbol} can be
627 set to @code{upright}, @code{italics} or @code{caps}.
629 You will notice that that @code{font-series} and @code{font-size}
630 are also listed there.
631 This immediately raises the question: Why are the common font
632 properties @code{font-series} and @code{font-size} listed under
633 @code{LyricText} as well as under the interface
634 @code{font-interface} but @code{font-shape} is not? The answer
635 is that @code{font-series} and @code{font-size} are changed
636 from their global default values when a @code{LyricText} object
637 is created, but @code{font-shape} is not. The entries in
638 @code{LyricText} then tell you the values for those two
639 properties which apply to @code{LyricText}. Other objects
640 which support @code{font-interface} will set these
641 properties diferently when they are created.
643 Let's see if we can now construct the @code{\override} command
644 to change the lyrics to italics. The object is @code{LyricText},
645 the property is @code{font-shape} and the value is
646 @code{italic}. As before, we'll omit the context.
648 As an aside, although it is an important one, note that because
650 @code{font-shape} are symbols they must be introduced with a
651 single apostrophe, @code{'}. That is why apostrophes
652 are needed before @code{thickness} in the earlier example
653 and @code{font-shape}. These are both symbols too.
654 Symbols are special names which are known internally to
655 LilyPond. Some of them are the names of properties,
656 like @code{thickness} or @code{font-shape}, others are in
657 effect special values that can be given to properties, like
658 @code{italic}. Note the distinction from arbitary
659 text strings, which would appear as @code{"a text string"}.
661 Ok, so the @code{\override} command we need to print the lyrics
665 \override LyricText #'font-shape = #'italic
669 and this should be placed just in front of and close to the
670 lyrics which it should affect, like this:
672 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
677 g[( e]) e d[( f]) a |
681 \override LyricText #'font-shape = #'italic
682 The man who feels love's sweet e -- mo -- tion
688 and the lyrics are all printed in italics.
690 @subheading Specifying context in lyric mode
691 @cindex context, specifying in lyric mode
693 In the case of lyrics, if you try specifying the context in the
694 format given earlier the command will fail. A syllable
695 entered in lyricmode is terminated by either a space,
696 a newline or a digit. All other characters are included
697 as part of the syllable. For this reason a space or newline
698 must appear before the terminating @code{@}} to prevent it being
699 included as part of the final syllable. Similarly,
700 spaces must be inserted before and after the
701 period or dot, @q{.}, separating the context name from the
702 object name, as otherwise the two names are run together and
703 the interpreter cannot recognise them. So the command should be:
706 \override Lyrics . LyricText #'font-shape = #'italic
709 @warning{In lyrics always leave whitespace between the final
710 syllable and the terminating brace.}
712 @warning{In overrides in lyrics always place spaces around
713 the dot between the context name and the object name.}
715 @node Types of properties
716 @subsection Types of properties
718 @cindex Property types
720 So far we have seen two types of property: @code{number} and
721 @code{symbol}. To be valid, the value given to a property
722 must be of the correct type and obey the rules for that type.
723 The type of property is always shown in brackets after the
724 property name in the IR. Here is a list of the types you may
725 need, together with the rules for that type, and some examples.
726 You must always add a hash symbol, @code{#}, of course,
727 to the front of these values when they are entered in the
728 @code{\override} command.
730 @multitable @columnfractions .2 .45 .35
731 @headitem Property type
735 @tab Either True or False, represented by #t or #f
736 @tab @code{#t}, @code{#f}
737 @item Dimension (in staff space)
738 @tab A positive decimal number (in units of staff space)
739 @tab @code{2.5}, @code{0.34}
741 @tab A valid direction constant or its numerical equivalent
742 @tab @code{#LEFT}, @code{#CENTER}, @code{#UP},
745 @tab A positive whole number
746 @tab @code{3}, @code{1}
748 @tab A bracketed set of items separated by spaces,
749 preceded by an apostrophe
750 @tab @code{'(left-edge staff-bar)}, @code{'(1)},
751 @code{'(1.0 0.25 0.5)}
753 @tab Any valid markup
754 @tab @code{\markup @{ \italic "cresc." @}}
756 @tab A fraction of a whole note constructed with the
758 @tab @code{(ly:make-moment 1 4)},
759 @code{(ly:make-moment 3 8)}
761 @tab Any positive or negative decimal value
762 @tab @code{3.5}, @code{-2.45}
763 @item Pair (of numbers)
764 @tab Two numbers separated by a @q{space . space} and enclosed
765 in brackets preceded by an apostrophe
766 @tab @code{'(2 . 3.5)}, @code{'(0.1 . -3.2)}
768 @tab Any of the set of permitted symbols for that property,
769 preceded by an apostrophe
770 @tab @code{'italic}, @code{'inside}
772 @tab A procedure or @code{#f} (to cause no action)
773 @tab @code{bend::print}, @code{ly:text-interface::print},
776 @tab A list of three items enclosed in brackets and preceded
777 by a hash sign, @code{#}.
778 @tab @code{#(#t #t #f)}
781 @node Appearance of objects
782 @section Appearance of objects
784 Let us now put what we have learnt into practice with a few
785 examples which show how tweaks may be used to change the
786 appearance of the printed music.
789 * Visibility and color of objects::
791 * Length and thickness of objects::
794 @node Visibility and color of objects
795 @subsection Visibility and color of objects
797 In the educational use of music we might wish to print a score
798 with certain elements omitted as an exercise for the student,
799 who is required to supply them. As a simple example,
800 let us suppose the exercise is to supply the missing bar lines
801 in a piece of music. But the bar lines are normally inserted
802 automatically. How do we prevent them printing?
804 Before we tackle this, let us remember that object properties
805 are grouped in what are called @emph{interfaces} -- see
806 @ref{Properties found in interfaces}. This is simply to
807 group together those properties that are commonly required
808 together -- if one of them is required for an object, so are
809 the others. Some objects then need the properties in some
810 interfaces, others need them from other interfaces. The
811 interfaces which contain the properties required by a
812 particular grob are listed in the IR at the bottom of the
813 page describing that grob, and those properties may be
814 viewed by looking at those interfaces.
816 We explained how to find information about grobs in
817 @ref{Properties of layout objects}. Using the same approach,
818 we go to the IR to find the layout object which prints
819 bar lines. Going via @emph{Backend} and @emph{All layout objects}
821 is a layout object called @code{BarLine}. Its properties include
822 two that control its visibility: @code{break-visibility} and
823 @code{stencil}. Barline also supports a number of interfaces,
824 including the @code{grob-interface}, where we find the
825 @code{transparent} and the @code{color} properties. All
826 of these can affect the visibility of bar lines (and, of course,
827 by extension, many other layout objects too.) Let's consider
828 each of these in turn.
831 @cindex stencil property
833 This property controls the appearance of the bar lines by specifying
834 the symbol (glyph) which should be printed. In common
835 with many other properties, it can be set to print nothing by
836 setting its value to @code{#f}. Let's try it, as before, omitting
837 the implied Context, @code{Voice}:
839 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
842 \override BarLine #'stencil = ##f
849 The bar lines are still printed. What is wrong? Go back to the
850 IR and look again at the page giving the properties of BarLine.
851 At the top of the page it says @qq{Barline objects are created
852 by: Bar_engraver}. Go to the @code{Bar_engraver} page.
854 it gives a list of Contexts in which the bar engraver operates.
855 All of them are of the type @code{Staff}, so the reason the
856 @code{\override} command failed to work as expected is because
857 @code{Barline} is not in the default @code{Voice} context.
859 is specified wrongly, the command simply does not work. No
860 error message is produced, and nothing is logged in the log
861 file. Let's try correcting it by adding the correct context:
863 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
866 \override Staff.BarLine #'stencil = ##f
873 Now the bar lines have vanished.
875 @subheading break-visibility
877 @cindex break-visibility property
879 We see from the @code{BarLine} properties in the IR that the
880 @code{break-visibility} property requires a vector of three
882 These control respectively whether bar lines are printed at
883 the end of a line, in the middle of lines, and at the beginning
884 of lines. For our example we want all bar lines to be suppressed,
885 so the value we need is @code{#(#f #f #f)}.
886 Let's try that, remembering
887 to include the @code{Staff} context. Note also that in writing
888 this value we have two hash signs before the opening bracket.
889 One is required as part of the value to introduce a vector,
890 and one is required, as always, to precede the value itself in
891 the @code{\override} command.
893 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
896 \override Staff.BarLine #'break-visibility = ##(#f #f #f)
903 And we see this too removes all the bar lines.
905 @subheading transparent
906 @cindex transparent property
908 We see from the properties specified in the @code{grob-interface}
909 page in the IR that the @code{transparent} property is a boolean.
911 should be set to @code{#t} to make the grob transparent.
912 In this next example let us make the time signature invisible
913 rather than the bar lines.
914 To do this we need to find the grob name for the time signature.
916 the @q{All layout objects} page in the IR to find the properties
917 of the @code{TimeSignature} layout object. This is produced by
918 the @code{Time_signature_engraver} which you can check also lives
919 in the @code{Staff} context and also supports the
920 @code{grob-interface}. So the command to make the time signature
923 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
926 \override Staff.TimeSignature #'transparent = ##t
934 The time signature is gone, but this command leaves a gap where
935 the time signature should be. Maybe this is what is wanted for
936 an exercise for the student to fill it in, but in other
937 circumstances a gap might be undesirable. To remove it, the
938 stencil for the time signature should be set to @code{#f}
941 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
944 \override Staff.TimeSignature #'stencil = ##f
952 and the difference is obvious: setting the stencil to @code{#f}
953 removes the object entirely; making the object @code{transparent}
954 leaves it where it is, but makes it invisible.
957 @cindex color property
959 Finally we could make the bar lines invisible by coloring
960 them white. The @code{grob-interface} specifies that the
961 color property value is a list, but there is no
962 explanation of what that list should be. The list it
963 requires is actually a list of values in internal units,
964 but, to avoid having to know what these are, several ways
965 are provided to specify colors. The first way is to use one
966 of the @q{normal} colours listed in the first table in
967 @ruser{List of colors}. To set the bar lines to white
970 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
973 \override Staff.BarLine #'color = #white
981 and again, we see the bar lines are not visible. Note that
982 @emph{white} is not preceded by an apostrophe -- it is not
983 a symbol, but a @emph{function}. When called, it provides
984 the list of internal values required to set the color to
985 white. The other colors in the normal list are functions
986 too. To convince yourself this is working you might like
987 to change the color to one of the other functions in the
993 The second way of changing the color is to use the list of
994 X11 color names in the second list in @ruser{List of colors}.
995 However, these must be preceded by another function, which
996 converts X11 color names into the list of internal values,
997 @code{x11-color}, like this:
999 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1002 \override Staff.BarLine #'color = #(x11-color 'white)
1004 g, a16 b8 c d4 e16 |
1010 Note that in this case the function @code{x11-color} takes
1011 a symbol as an argument, so the symbol must be preceded by
1012 an apostrophe and the two enclosed in brackets.
1017 There is yet a third function, one which converts RGB values into
1018 internal colors -- the @code{rgb-color} function. This takes
1019 three arguments giving the intensities of the red, green and
1020 blue colors. These take values in the range 0 to 1. So to
1021 set the color to red the value should be @code{(rgb-color 1 0 0)}
1022 and to white it should be @code{(rgb-color 1 1 1)}:
1024 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1027 \override Staff.BarLine #'color = #(rgb-color 1 1 1)
1029 g, a16 b8 c d4 e16 |
1034 Finally, there is also a grey scale available as part of the
1035 X11 set of colors. These range from black, @code{'grey0'},
1036 to white, @code{'grey100}, in steps of 1. Let's illustrate
1037 this by setting all the layout objects in our example to
1038 various shades of grey:
1040 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1043 \override Staff.StaffSymbol #'color = #(x11-color 'grey30)
1044 \override Staff.TimeSignature #'color = #(x11-color 'grey60)
1045 \override Staff.Clef #'color = #(x11-color 'grey60)
1046 \override Voice.NoteHead #'color = #(x11-color 'grey85)
1047 \override Voice.Stem #'color = #(x11-color 'grey85)
1048 \override Staff.BarLine #'color = #(x11-color 'grey10)
1050 g, a16 b8 c d4 e16 |
1056 Note the contexts associated with each of the layout objects.
1057 It is important to get these right, or the commands will not
1058 work! Remember, the context is the one in which the appropriate
1059 engraver is placed. The default context for engravers can be
1060 found by starting from the layout object, going from there to
1061 the engraver which produces it, and on the engraver page in the
1062 IR it tells you in which context the engraver will normally be
1066 @node Size of objects
1067 @subsection Size of objects
1069 Let us begin by looking again at the earlier example
1070 see @ref{Nesting music expressions}) which showed
1071 how to introduce a new temporary staff, as in an @rglos{ossia}.
1073 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1074 \new Staff ="main" {
1081 alignAboveContext = "main" }
1089 Ossia are normally written without clef and time signature, and
1090 are usually printed slightly smaller than the main staff. We
1091 already know now how to remove the clef and time signature --
1092 we simply set the stencil of each to @code{#f}, as follows:
1094 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1095 \new Staff ="main" {
1102 alignAboveContext = "main"
1105 \override Staff.Clef #'stencil = ##f
1106 \override Staff.TimeSignature #'stencil = ##f
1116 where the extra pair of braces after the @code{\with} clause are
1117 required to ensure the enclosed overrrides and music are applied
1120 But what is the difference between modifying the staff context by
1121 using @code{\with} and modifying the stencils of the clef and the
1122 time signature with \override? The main difference is that
1123 changes made in a @code{\with} clause are made at the time the
1124 context is created, and remain in force as the @strong{default}
1125 values for the duration of that context, whereas
1126 @code{\set} or @code{\override} commands embedded in the
1127 music are dynamic -- they make changes synchronised with
1128 a particular point in the music. If changes are unset or
1129 reverted using @code{\unset} or @code{\revert} they return to
1130 their default values, which will be the ones set in the
1131 @code{\with} clause, or if none have been set there, the normal
1134 Some context properties
1135 can be modified only in @code{\with} clauses. These are those
1136 properties which cannot sensibly be changed after the context
1137 has been created. @code{alignAboveContext} and its partner,
1138 @code{alignBelowContext}, are two such properties -- once the
1139 staff has been created its alignment is decided and it would
1140 make no sense to try to change it later.
1142 The default values of layout object properties can also be set
1143 in @code{\with} clauses. Simply use the normal @code{\override}
1144 command leaving out the context name, since this is unambiguously
1145 defined as the context which the @code{\with} clause is modifying.
1146 If fact, an error will be generated if a context is specified
1149 So we could replace the example above with
1151 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1152 \new Staff ="main" {
1159 alignAboveContext = "main"
1160 % Don't print clefs in this staff
1161 \override Clef #'stencil = ##f
1162 % Don't print time signatures in this staff
1163 \override TimeSignature #'stencil = ##f
1172 Finally we come to changing the size of layout objects.
1174 Some layout objects are created as glyphs selected from
1175 a typeface font. These include note heads, accidentals, markup,
1176 clefs, time signatures, dynamics and lyrics.
1177 Their size is changed by modifying the
1178 @code{font-size} property, as we shall shortly see. Other
1179 layout objects such as slurs and ties -- in general, spanner
1180 objects -- are drawn individually, so there is no
1182 associated with them. These objects generally derive their
1183 size from the objects to which they are attached, so usually
1184 there is no need to change their size manually. Still other
1185 properties such as the length of stems and bar lines, thickness
1186 of beams and other lines, and the separation of staff lines all
1187 need to be modified in special ways.
1189 Returning to the ossia example, let us first change the font-size.
1190 We can do this in two ways. We can either change the size of the
1191 fonts of each object type, like @code{NoteHead}s with commands
1195 \override NoteHead #'font-size = #-2
1198 or we can change the size of all fonts by setting a special
1199 property, @code{fontSize}, using @code{\set}, or by including
1200 it in a @code{\with} clause (but without the @code{\set}).
1206 Both of these statements would cause the font size to be reduced
1207 by 2 steps from its previous value, where each
1208 step reduces or increases the size by approximately 12%.
1210 Let's try it in our ossia example:
1212 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1213 \new Staff ="main" {
1220 alignAboveContext = "main"
1221 \override Clef #'stencil = ##f
1222 \override TimeSignature #'stencil = ##f
1223 % Reduce all font sizes by ~24%
1233 This is still not quite right. The note heads and flags are
1234 smaller, but the stems are too long in proportion and the
1235 staff lines are spaced too widely apart. These need to be
1236 scaled down in proportion to the font reduction. The next
1237 sub-section discusses how this is done.
1239 @node Length and thickness of objects
1240 @subsection Length and thickness of objects
1246 @cindex size, changing
1247 @cindex stem length, changing
1248 @cindex staff line spacing, changing
1250 Distances and lengths in LilyPond are generally measured in
1251 staff-spaces, the distance between adjacent lines in the staff,
1252 (or occasionally half staff spaces) while most @code{thickness}
1253 properties are measured in units of an internal property called
1254 @code{line-thickness.} For example, by default, the lines of
1255 hairpins are given a thickness of 1 unit of @code{line-thickness},
1256 while the @code{thickness} of a note stem is 1.3. Note, though,
1257 that some thickness properties are different; for example, the
1258 thickness of beams is measured in staff-spaces.
1260 So how are lengths to be scaled in proportion to the font size?
1261 This can be done with the help of a special function called
1262 @code{magstep} provided for exactly this purpose. It takes
1263 one argument, the change in font size (#-2 in the example above)
1264 and returns a scaling factor suitable for reducing other
1265 objects in proportion. It is used like this:
1267 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1268 \new Staff ="main" {
1275 alignAboveContext = "main"
1276 \override Clef #'stencil = ##f
1277 \override TimeSignature #'stencil = ##f
1279 % Reduce stem length and line spacing to match
1280 \override StaffSymbol #'staff-space = #(magstep -2)
1290 Since the length of stems and many other length-related properties
1291 are always calculated relative to the
1292 value of the @code{staff-space} property these are automatically
1293 scaled down in length too. Note that this affects only the
1294 vertical scale of the ossia -- the horizontal scale is determined
1295 by the layout of the main music in order to remain synchronised
1296 with it, so it is not affected by any of these changes in size.
1297 Of course, if the scale of all the main music were changed in this
1298 way then the horizontal spacing would be affected. This is
1299 discussed later in the layout section.
1301 This, then, completes the creation of an ossia. The sizes and
1302 lengths of all other objects may be modified in analogous ways.
1304 For small changes in scale, as in the example above, the
1305 thickness of the various drawn lines such as bar lines,
1306 beams, hairpins, slurs, etc does not usually require global
1307 adjustment. If the thickness of any particular layout object
1308 needs to be adjusted this can be best achieved by overriding its
1309 @code{thickness} property. An example of changing the thickness
1310 of slurs was shown above in @ref{Properties of layout objects}.
1311 The thickness of all drawn objects (i.e., those not produced
1312 from a font) may be changed in the same way.
1315 @node Placement of objects
1316 @section Placement of objects
1319 * Automatic behaviour::
1320 * Within-staff objects::
1321 * Outside staff objects::
1325 @node Automatic behaviour
1326 @subsection Automatic behaviour
1328 There are some objects in musical notation that belong to
1329 the staff and there are other objects that should be
1330 placed outside the staff. These are called within-staff
1331 objects and outside-staff objects respectively.
1333 Within-staff objects are those that are located on the staff
1334 -- note heads, stems, accidentals, etc. The positions of
1335 these are usually fixed by the music itself -- they are
1336 vertically positioned on specific lines of the staff or are
1337 tied to other objects that are so positioned. Collisions of
1338 note heads, stems and accidentals in closely set chords are
1339 normally avoided automatically. There are commands and
1340 overrides which can modify this automatic behaviour, as we
1343 Objects belonging outside the staff include things such as
1344 rehearsal marks, text and dynamic markings. LilyPond's rule for
1345 the vertical placement of outside-staff objects is to place them
1346 as close to the staff as possible but not so close that they
1347 collide with any other object. LilyPond uses the
1348 @code{outside-staff-priority} property to determine the order in
1349 which the objects should be placed, as follows.
1351 First, LilyPond places all the within-staff objects.
1352 Then it sorts the outside-staff objects according to their
1353 @code{outside-staff-priority}. The outside-staff objects are
1354 taken one by one, beginning with the object with the lowest
1355 @code{outside-staff-priority}, and placed so that they do not
1356 collide with any objects that have already been placed. That is,
1357 if two outside-staff grobs are competing for the same space, the
1358 one with the lower @code{outside-staff-priority} will be placed
1359 closer to the staff. If two objects have the same
1360 @code{outside-staff-priority} the one encountered first will be
1361 placed closer to the staff.
1363 In the following example all the markup texts have the same
1364 priority (since it is not explicity set). Note that @q{Text3}
1365 is automatically positioned close to the staff again, nestling
1368 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1375 Staves are also positioned, by default, as closely together as
1376 possible (subject to a minimum separation). If notes project
1377 a long way towards an adjacent staff they will force the
1378 staves further apart only if an overlap of the notation
1379 would otherwise occur. The following example demonstrates
1380 this @q{nestling} of the notes on adjacent staves:
1382 @lilypond[quote,ragged-right,verbatim]
1385 \relative c' { c a, }
1388 \relative c'''' { c a, }
1394 @node Within-staff objects
1395 @subsection Within-staff objects
1397 We have already seen how the commands @code{\voiceXXX} affect
1398 the direction of slurs, ties, fingering and
1399 everything else which depends on the direction of the stems.
1400 These commands are essential when writing polyphonic music to
1401 permit interweaving melodic lines to be distinguished.
1402 But occasionally it may be necessary to override this automatic
1403 behaviour. This can be done for whole sections of music or even
1404 for an individual note. The property which controls this
1405 behaviour is the @code{direction} property of each layout object.
1406 We first explain what this does, and then introduce a number of
1407 ready-made commands which avoid your having to code explicit
1408 overrides for the more common modifications.
1410 Some layout objects like slurs and ties curve, bend or point
1411 either up or down; others like stems and flags also move to
1412 right or left when they point up or down. This is controlled
1413 automatically when @code{direction} is set.
1415 The following example shows in bar 1 the default behaviour of
1417 with those on high notes pointing down and those on low notes
1418 pointing up, followed by four notes with all stems forced down,
1419 four notes with all stems forced up, and finally four notes
1420 reverted back to the default behaviour.
1422 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1424 \override Stem #'direction = #DOWN
1426 \override Stem #'direction = #UP
1428 \revert Stem #'direction
1432 Here we use the constants @code{DOWN} and @code{UP}.
1433 These have the values @code{-1} and @code{+1} respectively, and
1434 these numerical values may be used instead. The value @code{0}
1435 may also be used in some cases. It is simply treated as meaning
1436 @code{UP} for stems, but for some objects it means @q{center}.
1437 There is a constant, @code{CENTER} which has the value @code{0}.
1439 However, these explicit overrides are not usually used, as there
1440 are simpler equivalent predefined commands available.
1441 Here is a table of the commonest. The meaning of each is stated
1442 where it is not obvious.
1444 @multitable @columnfractions .2 .2 .2 .4
1449 @item @code{\arpeggioDown}
1450 @tab @code{\arpeggioUp}
1451 @tab @code{\arpeggioNeutral}
1452 @tab Arrow is at bottom, at top, or no arrow
1453 @item @code{\dotsDown}
1455 @tab @code{\dotsNeutral}
1456 @tab Direction of movement to avoid staff lines
1457 @item @code{\dynamicDown}
1458 @tab @code{\dynamicUp}
1459 @tab @code{\dynamicNeutral}
1461 @item @code{\phrasingSlurDown}
1462 @tab @code{\phrasingSlurUp}
1463 @tab @code{\phrasingSlurNeutral}
1464 @tab Note: distinct from slur commands
1465 @item @code{\slurDown}
1467 @tab @code{\slurNeutral}
1469 @item @code{\stemDown}
1471 @tab @code{\stemNeutral}
1473 @item @code{\textSpannerDown}
1474 @tab @code{\textSpannerUp}
1475 @tab @code{\textSpannerNeutral}
1476 @tab Text entered as spanner is below/above staff
1477 @item @code{\tieDown}
1479 @tab @code{\tieNeutral}
1481 @item @code{\tupletDown}
1482 @tab @code{\tupletUp}
1483 @tab @code{\tupletNeutral}
1484 @tab Tuplets are below/above notes
1487 Note that these predefined commands may @strong{not} be
1488 preceded by @code{\once}. If you wish to limit the
1489 effect to a single note you must either use the equivalent
1490 @code{\once \override} command or use the predefined command
1491 followed after the affected note by the corresponding
1492 @code{\xxxNeutral} command.
1494 @subheading Fingering
1495 @cindex fingering, placement
1497 The placement of fingering is also affected by the value
1498 of its @code{direction} property, but there are special
1499 commands which allow the fingering of individual notes
1500 of chords to be controlled, with the fingering being placed
1501 above, below, to the left or to the right of each note.
1503 First, here's the effect of @code{direction} on fingering,
1504 the first bar shows the default, then the effect of specifying
1505 @code{DOWN} and @code{UP}:
1507 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1509 \override Fingering #'direction = #DOWN
1511 \override Fingering #'direction = #UP
1515 This is how to control fingering on single notes, but the
1517 property is ignored for chords. Instead, by default, the
1518 fingering is automatically placed both above and below the
1519 notes of a chord, as shown:
1521 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1527 Greater control over the placement of fingering of the
1528 individual notes in a chord is possible by using
1529 the @code{\set fingeringOrientations} command. The format of
1533 @code{\set fingeringOrientations = #'([up] [left/right] [down])}
1537 @code{\set} is used because @code{fingeringOrientations} is a
1538 property of the @code{Voice} context, created and used by the
1539 @code{New_fingering_engraver}.
1541 The property may be set to a list of one to three values.
1542 It controls whether fingerings may be placed above (if
1543 @code{up} appears in the list), below (if @code{down} appears),
1544 to the left (if @code{left} appears, or to the right
1545 (if @code{right} appears). Conversely, if a location is not
1546 listed, no fingering is placed there. LilyPond takes these
1547 contraints and works out the best placement for the fingering
1548 of the notes of the following chords. Note that @code{left} and
1549 @code{right} are mutually exclusive -- fingering may be placed
1550 only on one side or the other, not both.
1552 To control the placement of the fingering of a single note
1553 using this command it is necessary to write it as a single
1554 note chord by placing angle brackets round it.
1556 Here are a few examples:
1558 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1559 \set fingeringOrientations = #'(left)
1561 < c-1 e-2 g-3 b-5 > 4
1562 \set fingeringOrientations = #'(left)
1564 < c-1 e-2 g-3 b-5 > 4
1565 \set fingeringOrientations = #'(up left down)
1567 < c-1 e-2 g-3 b-5 > 4
1568 \set fingeringOrientations = #'(up left)
1570 < c-1 e-2 g-3 b-5 > 4
1571 \set fingeringOrientations = #'(right)
1573 < c-1 e-2 g-3 b-5 > 4
1577 If the fingering seems a little crowded the @code{font-size}
1578 could be reduced. The default value can be seen from the
1579 @code{Fingering} object in the IR to be @code{-5}, so let's
1582 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1583 \override Fingering #'font-size = #-7
1584 \set fingeringOrientations = #'(left)
1586 < c-1 e-2 g-3 b-5 > 4
1587 \set fingeringOrientations = #'(left)
1589 < c-1 e-2 g-3 b-5 > 4
1590 \set fingeringOrientations = #'(up left down)
1592 < c-1 e-2 g-3 b-5 > 4
1593 \set fingeringOrientations = #'(up left)
1595 < c-1 e-2 g-3 b-5 > 4
1596 \set fingeringOrientations = #'(right)
1598 < c-1 e-2 g-3 b-5 > 4
1601 @node Outside staff objects
1602 @subsection Outside staff objects
1604 Outside-staff objects are automatically placed to avoid collisions.
1605 Objects with the lower value of the @code{outside-staff-priority}
1606 property are placed nearer to the staff, and other outside-staff
1607 objects are then raised as far as necessary to avoid collisions.
1608 The @code{outside-staff-priority} is defined in the
1609 @code{grob-interface} and so is a property of all layout objects.
1610 By default it is set to @code{#f} for all within-staff objects,
1611 and to a numerical value appropriate to each outside-staff object
1612 when the object is created. The following table shows
1613 the default numerical values for some of the commonest
1614 outside-staff objects which are, by default, placed in the
1615 @code{Staff} or @code{Voice} contexts.
1617 @multitable @columnfractions .3 .3 .3
1618 @headitem Layout Object
1620 @tab Controls position of:
1621 @item @code{MultiMeasureRestText}
1623 @tab Text over full-bar rests
1624 @item @code{TextScript}
1627 @item @code{OttavaBracket}
1629 @tab Ottava brackets
1630 @item @code{TextSpanner}
1633 @item @code{DynamicLineSpanner}
1635 @tab All dynamic markings
1636 @item @code{VoltaBracketSpanner}
1639 @item @code{TrillSpanner}
1641 @tab Spanning trills
1644 Here is an example showing the default placement of some of
1647 @cindex text spanner
1648 @funindex \startTextSpan
1649 @funindex \stopTextSpan
1650 @cindex ottava bracket
1652 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1653 % Set details for later Text Spanner
1654 \override TextSpanner #'bound-details #'left #'text
1655 = \markup { \small \bold Slower }
1656 % Place dynamics above staff
1658 % Start Ottava Bracket
1663 % Add Dynamic Line Spanner
1669 c\ff c \stopTextSpan
1670 % Stop Ottava Bracket
1675 This example also shows how to create Text Spanners --
1676 text with extender lines above a section of music. The
1677 spanner extends from the @code{\startTextSpan} command to
1678 the @code{\stopTextSpan} command, and the format of the
1679 text is defined by the @code{\override TextSpanner} command.
1680 For more details see @ruser{Text spanners}.
1682 It also shows how ottava brackets are created.
1684 Note that bar numbers, metronome marks and rehearsal marks
1685 are not shown. By default these are created in the
1686 @code{Score} context and their @code{outside-staff-priority}
1687 is ignored relative to the layout objects which are created
1688 in the @code{Staff} context.
1689 If you wish to place bar numbers, metronome marks or rehearsal
1690 marks in accordance with the value of their
1691 @code{outside-staff-priority} the @code{Bar_number_engraver},
1692 @code{Metronome_mark_engraver} or @code{Mark_engraver} respectively
1693 should be removed from the @code{Score} context and placed in the
1694 top @code{Staff} context. If this is done, these marks will be
1695 given the following default @code{outside-staff-priority} values:
1697 @multitable @columnfractions .3 .3
1698 @headitem Layout Object @tab Priority
1699 @item @code{RehearsalMark} @tab @code{1500}
1700 @item @code{MetronomeMark} @tab @code{1000}
1701 @item @code{BarNumber} @tab @code{ 100}
1704 If the default values of @code{outside-staff-priority} do not
1705 give you the placing you want, the priority of any of the objects
1706 may be overridden. Suppose we would
1707 like the ottava bracket to be placed below the text spanner in the
1708 example above. All we need to do is to look up the priority of
1709 @code{OttavaBracket} in the IR or in the tables above, and reduce
1710 it to a value lower than that of a @code{TextSpanner}, remembering
1711 that @code{OttavaBracket} is created in the @code{Staff} context:
1713 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1714 % Set details for later Text Spanner
1715 \override TextSpanner #'bound-details #'left #'text
1716 = \markup { \small \bold Slower }
1717 % Place dynamics above staff
1719 %Place following Ottava Bracket below Text Spanners
1720 \once \override Staff.OttavaBracket #'outside-staff-priority = #340
1721 % Start Ottava Bracket
1726 % Add Dynamic Line Spanner
1732 c\ff c \stopTextSpan
1733 % Stop Ottava Bracket
1738 Changing the @code{outside-staff-priority} can also be used to
1739 control the vertical placement of individual objects, although
1740 the results may not always be desirable. Suppose we would
1741 like @qq{Text3} to be placed above @qq{Text4} in the example
1742 under Automatic behaviour, above (see @ref{Automatic behaviour}).
1743 All we need to do is to look up the priority of @code{TextScript}
1744 in the IR or in the tables above, and increase the priority of
1745 @qq{Text3} to a higher value:
1747 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1750 \once \override TextScript #'outside-staff-priority = #500
1755 This certainly lifts @qq{Text3} above @qq{Text4} but it also
1756 lifts it above @qq{Text2}, and @qq{Text4} now drops down.
1757 Perhaps this is not so good. What we would really like to do
1758 is to position all the annotation at the same distance above
1759 the staff? To do this, we clearly
1760 will need to space the notes out horizontally to make more
1761 room for the text. This is done using the @code{textLengthOn}
1764 @subheading \textLengthOn
1766 @funindex \textLengthOn
1767 @cindex notes, spreading out with text
1769 By default, text produced by markup takes up no horizontal space
1770 as far as laying out the music is concerned. The @code{\textLengthOn}
1771 command reverses this behaviour, causing the notes to be spaced
1772 out as far as is necessary to accommodate the text:
1774 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1775 \textLengthOn % Cause notes to space out to accommodate text
1782 The command to revert to the default behaviour is
1783 @code{\textLengthOff}. Remember @code{\once} only works with
1784 @code{\override}, @code{\set}, @code{\revert} or @code{unset},
1785 so cannot be used with @code{\textLengthOn}.
1787 Markup text will also avoid notes which project above the staff.
1788 If this is not desired, the automatic displacement upwards may
1789 be turned off by setting the priority to @code{#f}. Here's an
1790 example to show how markup text interacts with such notes.
1792 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1793 % This markup is short enough to fit without collision
1797 % This is too long to fit, so it is displaced upwards
1801 % Turn off collision avoidance
1802 \once \override TextScript #'outside-staff-priority = ##f
1806 % Turn off collision avoidance
1807 \once \override TextScript #'outside-staff-priority = ##f
1808 \textLengthOn % and turn on textLengthOn
1809 c,,2^"Long Text " % Spaces at end are honoured
1814 @subheading Dynamics
1816 Dynamic markings will normally be positioned beneath the
1817 staff, but may be positioned above with the @code{dynamicUp}
1818 command. They will be positioned vertically relative to the
1819 note to which they are attached, and will float below (or above)
1820 all within-staff objects such as phrasing slurs and bar numbers.
1821 This can give quite acceptable results, as this example
1824 @lilypond[quote,fragment,ragged-right,verbatim,relative=1]
1829 bes4.~\f\< \( bes4 bes8 des4\ff\> c16 bes\! |
1830 ees,2.~\)\mf ees4 r8 |
1833 However, if the notes and attached dynamics are close
1834 together the automatic placement will avoid collisions
1835 by displacing later dynamic markings further away, but this may
1836 not be the optimum placement, as this rather artificial example
1839 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1845 Should a similar situation arise in @q{real} music, it may
1846 be preferable to space out the notes
1847 a little further, so the dynamic markings can all fit at the
1848 same vertical distance from the staff. We were able to do this
1849 for markup text by using the @code{\textLengthOn} command, but there
1850 is no equivalent command for dynamic marks. So we shall have to
1851 work out how to do this using @code{\override} commands.
1853 @subheading Grob sizing
1856 @cindex sizing grobs
1857 @cindex @code{X-offset}
1858 @cindex @code{Y-offset}
1859 @cindex @code{X-extent}
1860 @cindex @code{Y-extent}
1862 First we must learn how grobs are sized. All grobs have a
1863 reference point defined within them which is used to position
1864 them relative to their parent object. This point in the grob
1865 is then positioned at a horizontal distance, @code{X-offset},
1866 and at a vertical distance, @code{Y-offset}, from its parent.
1867 The horizontal extent of the object is given by a pair of
1868 numbers, @code{X-extent}, which say where the left and right
1869 edges are relative to the reference point. The vertical extent
1870 is similarly defined by a pair of numbers, @code{Y-extent}.
1871 These are properties of all grobs which support the
1872 @code{grob-interface}.
1874 @cindex @code{extra-spacing-width}
1876 By default, outside-staff objects are given a width of zero so
1877 that they may overlap in the horizontal direction. This is done
1878 by the trick of adding infinity to the leftmost extent and
1879 minus infinity to the rightmost extent by setting the
1880 @code{extra-spacing-width} to @code{'(+inf.0 . -inf.0)}. So
1881 to ensure they do not overlap in the horizontal direction we
1882 must override this value of @code{extra-spacing-width} to
1883 @code{'(0 . 0)} so the true width shines through. This is
1884 the command to do this for dynamic text:
1887 \override DynamicText #'extra-spacing-width = #'(0 . 0)
1891 Let's see if this works in our previous example:
1893 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1895 \override DynamicText #'extra-spacing-width = #'(0 . 0)
1900 Well, it has certainly stopped the dynamic marks being
1901 displaced, but two problems remain. The marks should be
1902 spaced a little further apart and it would be better
1903 if they were all the same distance from the staff.
1904 We can solve the first problem easily. Instead of making
1905 the @code{extra-spacing-width} zero we could add a little
1906 more to it. The units are the space between two staff
1907 lines, so moving the left edge half a unit to the left and the
1908 right edge half a unit to the right should do it:
1910 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
1912 % Extend width by 1 staff space
1913 \override DynamicText #'extra-spacing-width = #'(-0.5 . 0.5)
1918 This looks better, but maybe we would prefer the dynamic marks
1919 to be aligned along the same baseline rather than going up and
1920 down with the notes. The property to do this is
1921 @code{staff-padding} which is covered in the following section.
1924 @node Collisions of objects
1925 @section Collisions of objects
1929 * Fixing overlapping notation::
1930 * Real music example::
1933 @node Moving objects
1934 @subsection Moving objects
1936 This may come as a surprise, but LilyPond is not perfect. Some
1937 notation elements can overlap. This is unfortunate, but in fact
1938 rather rare. Usually the need to move objects is for clarity or
1939 aesthetic reasons -- they would look better with a little more
1940 or a little less space around them.
1942 There are three main main approaches to resolving overlapping
1943 notation. They should be considered in the following order:
1947 The @strong{direction} of one of the overlapping objects may
1948 be changed using the predefined commands listed above for
1949 within-staff objects (see @ref{Within-staff objects}).
1950 Stems, slurs, beams, ties, dynamics, text and tuplets may be
1951 repositioned easily in this way. The limitation is that you
1952 have a choice of only two positions, and neither may be
1956 The @strong{object properties}, which LilyPond uses
1957 when positioning layout objects, may be modified using
1958 @code{\override}. The advantages
1959 of making changes to this type of property are (a) that some
1960 other objects will be moved automatically if necessary to make
1961 room and (b) the single override can apply to all instances of
1962 the same type of object. Such properties include:
1968 This has already been covered in some detail -- see
1969 @ref{Within-staff objects}.
1972 @code{padding}, @code{left-padding},
1973 @code{right-padding}, @code{staff-padding}
1975 @cindex left-padding property
1976 @cindex padding property
1977 @cindex right-padding property
1978 @cindex staff-padding property
1979 As an object is being positioned the value of its @code{padding}
1980 property specifies the gap that must be left between itself and
1981 the nearest edge of the object against which it is being
1982 positioned. Note that it is the @code{padding} value of the object
1983 @strong{being placed} that is used;
1984 the @code{padding} value of the object which is already placed is
1985 ignored. Gaps specified by @code{padding} can be applied
1986 to all objects which support the @code{side-position-interface}.
1988 Instead of @code{padding}, the placement of groups of accidentals
1989 is controlled by @code{left-padding} and @code{right-padding}.
1990 These properties are to be found in the @code{AccidentalPlacement}
1991 object which, note, lives in the @strong{staff} context. Because
1992 accidentals are always positioned after and to the left of
1993 note heads only the @code{right-padding} property has any effect.
1995 The @code{staff-padding} property is closely related to the
1996 @code{padding} property: @code{padding}
1997 controls the minimum amount of space between any object which
1998 supports the @code{side-position-interface} and the nearest
1999 other object (generally the note or the staff lines);
2000 @code{staff-padding} applies only to those objects which are always
2001 set outside the staff -- it controls the minimum amount of space
2002 that should be inserted between that object and the staff. Note
2003 that @code{staff-padding} has no effect on objects which are
2004 positioned relative to the note rather than the staff, even though
2005 it may be overridden without error for such objects -- it is simply
2008 To discover which padding property is required for the object
2009 you wish to reposition, you
2010 need to return to the IR and look up the object's properties.
2011 Be aware that the padding properties might not be located in the
2012 obvious object, so look in objects that appear to be related.
2014 All padding values are measured in staff spaces. For most
2015 objects, this value is set by default to be around 1.0 or less
2016 (it varies with each object). It may be overridden if a larger
2017 (or smaller) gap is required.
2020 @code{self-alignment-X}
2022 @cindex self-alignment-X property
2023 This property can be used to align the object to the left, to
2024 the right, or to center it with respect to the parent object's
2025 reference point. It may be used with all objects which support
2026 the @code{self-alignment-interface}. In general these are objects
2027 that contain text. The values are @code{LEFT}, @code{RIGHT}
2028 or @code{CENTER}. Alternatively, a numerical value between
2029 @code{-1} and @code{+1} may be specified, where @code{-1} is
2030 left-aligned, @code{+1} is right-aligned, and numbers in between
2031 move the text progressively from left-aligned to right-aligned.
2032 Numerical values greater than @code{1} may be specified to move
2033 the text even further to the left, or less than @code{-1} to
2034 move the text even further to the right. A change of @code{1}
2035 in the value corresponds to a movement of half the text's length.
2038 @code{extra-spacing-width}
2040 @cindex extra-spacing-width property
2041 This property is available for all objects which support the
2042 @code{item-interface}. It takes two numbers, the first is added
2043 to the leftmost extent and the second is added to the rightmost
2044 extent. Negative numbers move the edge to the left, positive to
2045 the right, so to widen an object the first number must be negative,
2046 the second positive. Note that not all objects honour both
2047 numbers. For example, the @code{Accidental} object only takes
2048 notice of the first (left edge) number.
2051 @code{staff-position}
2053 @cindex staff-position property
2054 @code{staff-position} is a property of the
2055 @code{staff-symbol-referencer-interface}, which is supported by
2056 objects which are positioned relative to the staff. It specifies
2057 the vertical position of the object relative to the center line
2058 of the staff in half staff-spaces. It is useful in resolving
2059 collisions between layout objects like multi-measure rests, ties
2060 and notes in different voices.
2065 @cindex force-hshift property
2067 Closely spaced notes in a chord, or notes occuring at the same
2068 time in different voices, are arranged in two, occasionally more,
2069 columns to prevent the note heads overlapping. These are called
2070 note columns, and an object called @code{NoteColumn} is created
2071 to lay out the notes in that column.
2073 The @code{force-hshift}
2074 property is a property of a @code{NoteColumn} (actually of the
2075 @code{note-column-interface}). Changing it permits a note column
2076 to be moved in units appropriate to a note column, viz. the note
2077 head width of the first voice note. It should be used in
2078 complex situations where the normal @code{\shiftOn} commands (see
2079 @ref{Explicitly instantiating voices}) do
2080 not resolve the note conflict. It is preferable to the
2081 @code{extra-offset} property for this purpose as there is no need
2082 to work out the distance in staff-spaces, and moving the notes
2083 into or out of a @code{NoteColumn} affects other actions such as
2088 Objects do not all have all of these properties in general.
2089 It is necessary to go to the IR to look up which properties
2090 are available for the object in question.
2093 Finally, when all else fails, objects may be manually repositioned
2094 relative to the staff center line verically, or by
2095 displacing them by any distance to a new position. The
2096 disadvantages are that the correct values for the repositioning
2097 have to be worked out, often by trial and error, for every object
2098 individually, and, because the movement is done after LilyPond has
2099 placed all other objects, the user is responsible for avoiding any
2100 collisions that might ensue. But the main difficulty with this
2101 approach is that the repositioning values may need to be reworked
2102 if the music is later modified. The properties that can be used
2103 for this type of manual repositioning are:
2107 @cindex extra-offset property
2108 This property applies to any layout object
2109 supporting the @code{grob-interface}. It takes a pair of
2110 numbers which specify the extra displacement in the horizontal and
2111 vertical directions. Negative numbers move the object to
2112 the left or down. The units are staff-spaces. The extra
2113 displacement is made after the typesetting of objects is
2114 finished, so an object may be repositioned anywhere without
2115 affecting anything else.
2118 @cindex positions property
2119 This is most useful for manually adjusting the slope and height
2120 of beams, slurs, and tuplets. It takes a pair of numbers
2121 giving the position of the left and right ends of the beam, slur,
2122 etc. relative to the center line of the staff. Units are
2123 staff-spaces. Note, though, that slurs and phrasing slurs cannot
2124 be repositioned by arbitrarily large amounts. LilyPond first
2125 generates a list of possible positions for the slur and by default
2126 finds the slur that @qq{looks best}. If the @code{positions}
2127 property has been overridden the slur that is closest to the
2128 requested positions is selected from the list.
2131 Objects do not all have all of these properties in general.
2132 It is necessary to go to the IR to look up which properties
2133 are available for the object in question.
2137 Here is a list of the objects which are most likely to be
2138 involved in collisions, together with the name of the object which
2139 should be looked up in the IR in order to discover which properties
2140 should be used to move them.
2142 @multitable @columnfractions .5 .5
2143 @headitem Object type @tab Object name
2144 @item Articulations @tab @code{Script}
2145 @item Beams @tab @code{Beam}
2146 @item Dynamics (vertically) @tab @code{DynamicLineSpanner}
2147 @item Dynamics (horizontally) @tab @code{DynamicText}
2148 @item Fingerings @tab @code{Fingering}
2149 @item Rehearsal / Text marks @tab @code{RehearsalMark}
2150 @item Slurs @tab @code{Slur}
2151 @item Text e.g. @code{^"text"} @tab @code{TextScript}
2152 @item Ties @tab @code{Tie}
2153 @item Tuplets @tab @code{TupletBracket}
2157 @node Fixing overlapping notation
2158 @subsection Fixing overlapping notation
2160 Let's now see how the properties in the previous section can
2161 help to resolve overlapping notation.
2163 @subheading padding property
2164 @cindex padding property
2166 The @code{padding} property can be set to increase
2167 (or decrease) the distance between symbols that are printed
2168 above or below notes.
2170 @lilypond[quote,fragment,relative=1,verbatim]
2172 \override Script #'padding = #3
2176 @lilypond[quote,fragment,relative=1,verbatim]
2177 % This will not work, see below:
2178 \override MetronomeMark #'padding = #3
2182 \override Score.MetronomeMark #'padding = #3
2187 Note in the second example how important it is to figure out what
2188 context handles a certain object. Since the @code{MetronomeMark}
2190 is handled in the @code{Score} context, property changes in the
2191 @code{Voice} context will not be noticed. For more details, see
2192 @ruser{Constructing a tweak}.
2194 If the @code{padding} property of an object is increased when that
2195 object is in a stack of objects being positioned according to
2196 their @code{outside-staff-priority}, then that object and all
2197 objects outside it are moved.
2200 @subheading left-padding and right-padding
2201 @cindex left-padding property
2202 @cindex right-padding property
2204 The @code{right-padding} property affects the spacing between the
2205 accidental and the note to which it applies. It is not often
2206 required, but the following example shows one situation where it
2207 is needed. Suppose we wish to show a chord containing both
2208 a B-natural and a B-flat. To avoid ambiguity we would like to
2209 precede the notes with both a natural and a flat sign. Here
2210 are a few attempts to do this:
2212 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2218 None work, with the second two showing bad collisions between
2221 One way of achieving this is to override the accidental stencil
2222 with a markup containing the natural and flat symbols in the
2223 order we would like, like this:
2225 @lilypond[quote,ragged-right,verbatim]
2226 naturalplusflat = \markup { \natural \flat }
2228 \once \override Accidental
2229 #'stencil = #ly:text-interface::print
2230 \once \override Accidental #'text = #naturalplusflat
2231 \once \override Score.AccidentalPlacement #'right-padding = #1.5
2237 This necessarily uses an override for the accidental stencil which
2238 will not be covered until later. The stencil type must be a
2239 procedure, here changed to print the contents of the @code{text}
2240 property of @code{Accidental}, which itself is set to be a natural
2241 sign followed by a flat sign. These are then moved further away
2242 from the note head by overriding @code{right-padding}.
2246 @subheading staff-padding property
2247 @cindex staff-padding property
2249 @code{staff-padding} can be used to align objects such as dynamics
2250 along a baseline at a fixed height above the staff, rather than
2251 at a height dependent on the position of the note to which they
2252 are attached. It is not a property of
2253 @code{DynamicText} but of @code{DynamicLineSpanner}.
2254 This is because the baseline should apply equally to @strong{all}
2255 dynamics, including those created as extended spanners.
2256 So this is the way to align the dynamic marks in the example
2257 taken from the previous section:
2259 @lilypond[quote,fragment,ragged-right,verbatim,relative=2]
2261 % Extend width by 1 unit
2262 \override DynamicText #'extra-spacing-width = #'(-0.5 . 0.5)
2263 % Align dynamics to a base line 2 units above staff
2264 \override DynamicLineSpanner #'staff-padding = #2
2269 @subheading self-alignment-X property
2270 @cindex self-alignment-X property
2272 The following example shows how this can resolve the collision
2273 of a string fingering object with a note's stem by aligning the
2274 right edge with the reference point of the parent note:
2276 @lilypond[quote,fragment,ragged-right,verbatim,relative=3]
2279 \once \override StringNumber #'self-alignment-X = #RIGHT
2283 @subheading staff-position property
2284 @cindex staff-position property
2286 Multimeasure rests in one voice can collide with notes in another.
2287 Since these rests are typeset centered between the bar lines, it
2288 would require significant effort for LilyPond to figure out which
2289 other notes might collide with it, since all the current collision
2290 handling between notes and between notes and rests is done only
2291 for notes and rests that occur at the same time. Here's an
2292 example of a collision of this type:
2294 @lilypond[quote,verbatim,fragment,ragged-right, relative=1]
2295 << {c c c c} \\ {R1} >>
2298 The best solution here is to move the multimeasure rest down,
2299 since the rest is in voice two.
2300 The default in @code{\voiceTwo} (i.e. in the second voice of a
2301 @code{<<@{...@} \\ @{...@}>>} construct)
2302 is that @code{staff-position} is set to -4 for MultiMeasureRest,
2303 so we need to move it, say, four half-staff spaces down to
2306 @lilypond[quote,verbatim,fragment,ragged-right, relative=1]
2310 \override MultiMeasureRest #'staff-position = #-8
2315 This is better than using, for example, @code{extra-offset},
2316 because the ledger line above the rest is inserted automatically.
2318 @subheading extra-offset property
2319 @cindex extra-offset property
2321 The @code{extra-offset} property provides complete control over the
2322 positioning of an object both horizontally and vertically.
2324 In the following example, the second fingering is moved a little to
2325 the left, and 1.8 staff space downwards:
2327 @lilypond[quote,fragment,relative=1,verbatim]
2330 \once \override Fingering
2331 #'extra-offset = #'(-0.3 . -1.8)
2336 @subheading positions property
2337 @cindex positions property
2339 The @code{positions} property allows the position and slope of
2340 tuplets, slurs, phrasing slurs and beams to be controlled
2341 manually. Here's an example which has an ugly phrasing slur
2342 due to its trying to avoid the slur on the acciaccatura.
2344 @lilypond[quote,verbatim,fragment,ragged-right,relative=1]
2345 r4 \acciaccatura e8\( d8 c ~c d c d\)
2349 We could simply move the phrasing slur above the notes, and this
2350 would be the preferred solution:
2352 @lilypond[quote,verbatim,fragment,ragged-right,relative=1]
2355 \acciaccatura e8\( d8 c ~c d c d\)
2359 but if there were some reason why this could not be done the
2360 other alternative would be to move the left end of the phrasing
2361 slur down a little using the @code{positions} property. This
2362 also resolves the rather nasty shape.
2364 @lilypond[quote,verbatim,fragment,ragged-right,relative=1]
2366 \once \override PhrasingSlur #'positions = #'(-4 . -3)
2368 e8\( d8 c ~c d c d\)
2371 Here's a further example taken from the opening of the left-hand
2372 staff of Chopin's Prelude Op 28 No. 2. We see that the beam
2373 collides with the upper notes:
2375 @lilypond[quote,verbatim,fragment,ragged-right]
2378 << {b,8 ais, b, g,} \\ {e, g e, g} >>
2379 << {b,8 ais, b, g,} \\ {e, g e, g} >>
2384 This can be resolved by manually moving both ends of the beam
2385 up from their position at 2 staff-spaces above the center line to,
2388 @lilypond[quote,verbatim,fragment,ragged-right]
2392 \override Beam #'positions = #'(3 . 3)
2397 << {b,8 ais, b, g,} \\ {e, g e, g} >>
2402 Note that the override continues to apply in the first voice of
2403 the second block of quavers, but not to any of the beams in the
2406 @subheading force-hshift property
2407 @cindex force-hshift property
2408 @c FIXME: formatting stuff (ie not important right now IMO)
2409 @c @a nchor Chopin finally corrected TODOgp
2411 We can now see how to apply the final corrections to the Chopin
2412 example introduced at the end of @ref{I'm hearing Voices}, which
2413 was left looking like this:
2415 @lilypond[quote,verbatim,fragment,ragged-right]
2416 \new Staff \relative c'' {
2419 { c2 aes4. bes8 } \\
2431 The lower two notes of the first chord (i.e,
2432 those in the third voice) should not be shifted away from the
2433 note column of the higher two notes. To correct this we set
2434 @code{force-hshift}, which is a property of
2435 @code{NoteColumn}, of these notes to zero.
2436 The lower note of the second chord is best placed just to the
2437 right of the higher notes. We achieve this by setting
2438 @code{force-hshift} of this note to 0.5, ie half a note head's
2439 width to the right of the note column of the higher notes.
2441 Here's the final result:
2443 @lilypond[quote,verbatim,fragment,ragged-right]
2444 \new Staff \relative c'' {
2447 { c2 aes4. bes8 } \\
2450 \once \override NoteColumn #'force-hshift = #0 <ees c>2
2451 \once \override NoteColumn #'force-hshift = #0.5 des2
2459 @node Real music example
2460 @subsection Real music example
2462 We end this section on Tweaks by showing the steps to be taken to
2463 deal with a tricky example which needs several tweaks to produce
2464 the desired output. The example has been deliberately chosen to
2465 illustrate the use of the Notation Reference to resolve unusual
2466 problems with notation. It is not representative of more usual
2467 engraving process, so please do not let these difficulties put
2468 you off! Fortunately, difficulties like these are not very common!
2470 The example is from Chopin's Première Ballade, Op. 23, bars 6 to
2471 9, the transition from the opening Lento to Moderato.
2472 Here, first, is what we want the output to look like, but to avoid
2473 over-complicating the example too much we have left out the
2474 dynamics, fingering and pedalling.
2476 @c The following should appear as music without code
2477 @lilypond[quote,ragged-right]
2478 rhMusic = \relative c'' {
2481 \once \override Tie #'staff-position = #3.5
2485 \override Staff.NoteCollision #'merge-differently-headed = ##t
2486 \override Staff.NoteCollision #'merge-differently-dotted = ##t
2487 bes2.^\markup {\bold "Moderato"} r8
2489 {c,8[ d fis bes a] | }
2491 % Reposition the c2 to the right of the merged note
2492 {c,8~ \once \override NoteColumn #'force-hshift = #1.0
2493 % Move the c2 out of the main note column so the merge will work
2496 % Stem on the d2 must be down to permit merging
2497 {s8 \stemDown \once \override Stem #'transparent = ##t d2}
2501 \revert Staff.NoteCollision #'merge-differently-headed
2502 \revert Staff.NoteCollision #'merge-differently-dotted
2506 lhMusic = \relative c' {
2508 <d g, d>1)\arpeggio |
2515 \new Staff = "RH" <<
2519 \new Staff = "LH" <<
2528 We note first that the right hand part in the third bar
2529 requires four voices. These are the five beamed eighth notes,
2530 the tied C, the half-note D which is merged with the eighth note
2531 D, and the dotted quarter note F-sharp, which is also merged with
2532 the eighth note at the same pitch. Everything else is in a single
2533 voice, so the easiest way is to introduce these four voices
2534 temporarily at the time they are needed. If you have forgotten
2535 how to do this, look at @ref{I'm hearing Voices}. Let us begin
2536 by entering the notes as two variables and setting up the staff
2537 structure in a score block, and see what LilyPond produces by
2540 @lilypond[quote,verbatim,ragged-right]
2541 rhMusic = \relative c'' {
2546 % Start polyphonic section of four voices
2548 {c,8 d fis bes a | }
2559 lhMusic = \relative c' {
2568 \new Staff = "RH" <<
2572 \new Staff = "LH" <<
2581 All the notes are right, but the appearance is far from
2582 satisfactory. The tie clashes with the change in time signature,
2583 the beaming in the third bar is wrong, the notes are not
2584 merged together, and several notation elements are missing.
2585 Let's first deal with the easier things.
2586 We can correct the beaming by inserting a beam
2587 manually, and we can easily add the left hand slur and the right
2588 hand phrasing slur, since these were all covered in the Tutorial.
2591 @lilypond[quote,verbatim,ragged-right]
2592 rhMusic = \relative c'' {
2597 % Start polyphonic section of four voices
2599 {c,8[ d fis bes a] | }
2610 lhMusic = \relative c' {
2619 \new Staff = "RH" <<
2623 \new Staff = "LH" <<
2632 The first bar is now correct. The second bar contains an arpeggio
2633 and is terminated by a double bar line. How do we do these, as they
2634 have not been mentioned in this Learning Manual? This is where
2635 we need to turn to the Notation Reference. Looking up @q{arpeggio}
2636 and @q{bar line} in the
2637 index quickly shows us that an arpeggio is produced by appending
2638 @code{\arpeggio} to a chord, and a double bar line is produced by
2639 the @code{\bar "||"} command. That's easily done. We next need
2640 to correct the collision of the tie with the time signature. This
2641 is best done by moving the tie upwards. Moving objects was covered
2642 earlier in @ref{Moving objects}, which says that objects positioned
2643 relative to the staff can be moved by overriding their
2644 @code{staff-position} property, which is specified in half staff
2645 spaces relative to the center line of the staff. So the following
2646 override placed just before the first tied note would move the tie
2647 up to 3.5 half staff spaces above the center line:
2649 @code{\once \override Tie #'staff-position = #3.5}
2651 This completes bar two, giving:
2653 @lilypond[quote,verbatim,ragged-right]
2654 rhMusic = \relative c'' {
2656 \once \override Tie #'staff-position = #3.5
2661 % Start polyphonic section of four voices
2663 {c,8[ d fis bes a] | }
2674 lhMusic = \relative c' {
2676 <d g, d>1)\arpeggio |
2683 \new Staff = "RH" <<
2687 \new Staff = "LH" <<
2696 On to bar three and the start of the Moderato section. The
2697 tutorial showed how to add embolded text with the
2698 @code{\markup} command, so adding @q{Moderato} in bold is easy.
2699 But how do we merge notes in different voices together? The
2700 index in the Notation Reference does not mention merging,
2701 but a search of the text for @q{merge} quickly leads us to
2702 the overrides for merging differently headed and differently
2703 dotted notes in @ruser{Collision Resolution}. In our
2704 example we need to merge both types of note for the duration
2705 of the polyphonic section in bar 3, so using the information
2706 in the Notation Reference we add
2709 \override Staff.NoteCollision #'merge-differently-headed = ##t
2710 \override Staff.NoteCollision #'merge-differently-dotted = ##t
2714 to the start of that section and
2717 \revert Staff.NoteCollision #'merge-differently-headed
2718 \revert Staff.NoteCollision #'merge-differently-dotted
2724 @lilypond[quote,verbatim,ragged-right]
2725 rhMusic = \relative c'' {
2727 \once \override Tie #'staff-position = #3.5
2731 bes2.^\markup {\bold "Moderato"} r8
2732 \override Staff.NoteCollision #'merge-differently-headed = ##t
2733 \override Staff.NoteCollision #'merge-differently-dotted = ##t
2734 % Start polyphonic section of four voices
2736 {c,8[ d fis bes a] | }
2744 \revert Staff.NoteCollision #'merge-differently-headed
2745 \revert Staff.NoteCollision #'merge-differently-dotted
2749 lhMusic = \relative c' {
2751 <d g, d>1)\arpeggio |
2758 \new Staff = "RH" <<
2762 \new Staff = "LH" <<
2771 These overrides have merged the two F-sharp notes, but not the two
2772 on D. Why not? The answer is there in the same section in the
2773 Notation Reference -- notes being merged must have stems in
2774 opposite directions and two notes cannot be merged successfully if
2775 there is a third note in the same note column. Here the two D's
2776 both have upward stems and there is a third note -- the C. We know
2777 how to change the stem direction using @code{\stemDown}, and
2778 the Notation Reference also says how to move the C -- apply a shift
2779 using one of the @code{\shift} commands. But which one?
2780 The C is in voice two which has shift off, and the two D's are in
2781 voices one and three, which have shift off and shift on,
2782 respectively. So we have to shift the C a further level still
2783 using @code{\shiftOnn} to avoid it interferring with the two D's.
2784 Applying these changes gives:
2786 @lilypond[quote,verbatim,ragged-right]
2787 rhMusic = \relative c'' {
2789 \once \override Tie #'staff-position = #3.5
2793 bes2.^\markup {\bold "Moderato"} r8
2794 \override Staff.NoteCollision #'merge-differently-headed = ##t
2795 \override Staff.NoteCollision #'merge-differently-dotted = ##t
2796 % Start polyphonic section of four voices
2798 {c,8[ d fis bes a] | }
2800 % Move the c2 out of the main note column so the merge will work
2801 {c,8~ \shiftOnn c2 | }
2803 % Stem on the d2 must be down to permit merging
2804 {s8 \stemDown d2 | }
2808 \revert Staff.NoteCollision #'merge-differently-headed
2809 \revert Staff.NoteCollision #'merge-differently-dotted
2813 lhMusic = \relative c' {
2815 <d g, d>1)\arpeggio |
2822 \new Staff = "RH" <<
2826 \new Staff = "LH" <<
2835 Nearly there. Only two problems remain: The downward stem on the
2836 merged D should not be there, and the C would be better positioned
2837 to the right of the D's. We know how to do both of these from the
2838 earlier tweaks: we make the stem transparent, and move the C with
2839 the @code{force-hshift} property. Here's the final result:
2841 @lilypond[quote,verbatim,ragged-right]
2842 rhMusic = \relative c'' {
2845 \once \override Tie #'staff-position = #3.5
2849 bes2.^\markup {\bold "Moderato"} r8
2850 \override Staff.NoteCollision #'merge-differently-headed = ##t
2851 \override Staff.NoteCollision #'merge-differently-dotted = ##t
2853 {c,8[ d fis bes a] | }
2855 % Reposition the c2 to the right of the merged note
2856 {c,8~ \once \override NoteColumn #'force-hshift = #1.0
2857 % Move the c2 out of the main note column so the merge will work
2860 % Stem on the d2 must be down to permit merging
2861 {s8 \stemDown \once \override Stem #'transparent = ##t d2}
2865 \revert Staff.NoteCollision #'merge-differently-headed
2866 \revert Staff.NoteCollision #'merge-differently-dotted
2870 lhMusic = \relative c' {
2872 <d g, d>1)\arpeggio |
2879 \new Staff = "RH" <<
2883 \new Staff = "LH" <<
2893 @node Further tweaking
2894 @section Further tweaking
2897 * Other uses for tweaks::
2898 * Using variables for tweaks::
2899 * Other sources of information::
2900 * Avoiding tweaks with slower processing::
2901 * Advanced tweaks with Scheme::
2904 @node Other uses for tweaks
2905 @subsection Other uses for tweaks
2909 @cindex transparent property, use of
2910 @cindex objects, making invisible
2911 @cindex removing objects
2912 @cindex objects, removing
2913 @cindex hiding objects
2914 @cindex invisible objects
2915 @cindex tying notes across voices
2918 @subheading Tying notes across voices
2920 The following example demonstrates how to connect notes in
2921 different voices using ties. Normally, only two notes in the
2922 same voice can be connected with ties. By using two voices,
2923 with the tied notes in one of them
2925 @lilypond[quote,fragment,relative=2]
2926 << { b8~ b8\noBeam }
2932 and blanking the first up-stem in that voice, the tie appears to
2935 @lilypond[quote,fragment,relative=2,verbatim]
2938 \once \override Stem #'transparent = ##t
2946 To make sure that the just-blanked stem doesn't squeeze the tie
2947 too much, we can lengthen the stem by setting the
2948 @code{length} to @code{8},
2950 @lilypond[quote,fragment,relative=2,verbatim]
2953 \once \override Stem #'transparent = ##t
2954 \once \override Stem #'length = #8
2963 @subheading Simulating a fermata
2965 @cindex stencil property, use of
2966 @cindex fermata, implementing in MIDI
2968 For outside-staff objects it is usually better to override the
2969 object's @code{stencil} property rather than its @code{transparent}
2970 property when you wish to remove it from the printed output.
2971 Setting the @code{stencil} property of an object to @code{#f} will
2972 remove that object entirely from the printed output. This means it
2973 has no effect on the placement of other objects placed relative to
2976 For example, if we wished to change the metronome setting in order
2977 to simulate a fermata in the MIDI output we would not want the
2978 metronome markings to appear in the printed output, and we would
2979 not want it to influence the spacing between the two systems or
2980 the spacing of the notes on the staff. So setting its
2981 @code{stencil} property to @code{#f} would be the best way.
2982 We show here the effect of the two methods:
2984 @lilypond[quote,verbatim,ragged-right]
2987 % Visible tempo marking
2990 \once \override Score.MetronomeMark #'transparent = ##t
2991 % Invisible tempo marking to lengthen fermata note in MIDI
2994 \once \override Score.MetronomeMark #'stencil = ##f
2995 % Invisible tempo marking to restore tempo in MIDI
3005 Both methods remove the metronome mark from the printed output,
3006 and both affect the MIDI timing as required, but the first
3007 (transparent) metronome mark still influences the note spacing
3008 while the second (with no stencil) does not.
3012 @node Using variables for tweaks
3013 @subsection Using variables for tweaks
3015 Override commands are often long and tedious to type, and they
3016 have to be absolutely correct. If the same overrides are to be
3017 used many times it may be worth defining variables to hold them.
3018 Suppose we wish to emphasize certain words in lyrics by printing
3019 them in bold italics. The @code{\italic} and @code{\bold}
3020 commands do not work within lyrics so we must instead use the
3021 following @code{\override} and @code{\revert} commands:
3024 @code{\override Lyrics . LyricText #'font-shape = #'italic}
3025 @code{\override Lyrics . LyricText #'font-series = #'bold}
3027 @code{\revert Lyrics . LyricText #'font-shape}
3028 @code{\revert Lyrics . LyricText #'font-series}
3031 These would be extremely tedious to enter if there were many words
3032 requiring emphasis. So instead we define these as two variables,
3033 and use them as follows:
3035 @lilypond[quote,verbatim]
3037 \override Lyrics . LyricText #'font-shape = #'italic
3038 \override Lyrics . LyricText #'font-series = #'bold
3041 \revert Lyrics . LyricText #'font-shape
3042 \revert Lyrics . LyricText #'font-series
3045 global = { \time 4/4 \partial 4 \key c \major}
3046 SopMusic = \relative c' { c4 | e4. e8 g4 g | a a g }
3047 AltoMusic = \relative c' { c4 | c4. c8 e4 e | f f e }
3048 TenorMusic = \relative c { e4 | g4. g8 c4. b8 | a8 b c d e4 }
3049 BassMusic = \relative c { c4 | c4. c8 c4 c | f8 g a b c4 }
3050 VerseOne = \lyrics { E -- | ter -- nal \emph Fa -- ther, \norm | strong to save, }
3051 VerseTwo = \lyricmode { O | \emph Christ, \norm whose voice the | wa -- ters heard, }
3052 VerseThree = \lyricmode { O | \emph Ho -- ly Spi -- rit, \norm | who didst brood }
3053 VerseFour = \lyricmode { O | \emph Tri -- ni -- ty \norm of | love and pow'r }
3059 \new Voice = "Sop" { \voiceOne \global \SopMusic }
3060 \new Voice = "Alto" { \voiceTwo \AltoMusic }
3061 \new Lyrics \lyricsto "Sop" { \VerseOne }
3062 \new Lyrics \lyricsto "Sop" { \VerseTwo }
3063 \new Lyrics \lyricsto "Sop" { \VerseThree }
3064 \new Lyrics \lyricsto "Sop" { \VerseFour }
3068 \new Voice = "Tenor" { \voiceOne \TenorMusic }
3069 \new Voice = "Bass" { \voiceTwo \BassMusic }
3077 @node Other sources of information
3078 @subsection Other sources of information
3080 The Internals Reference documentation contains a lot of information
3081 about LilyPond, but even more information can be gathered by
3082 looking at the internal LilyPond files. To explore these, first
3083 find the directory appropriate to your system, as follows:
3088 @file{@var{installdir}/lilypond/usr/share/lilypond/current/}
3093 @file{@var{installdir}/LilyPond.app/Contents/Resources/share/lilypond/current/}
3094 by either @code{cd}-ing into this directory from the
3095 Terminal, or control-clicking on the LilyPond application and
3096 selecting @q{Show Package Contents}.
3100 Using Windows Explorer, navigate to
3101 @file{@var{installdir}/LilyPond/usr/share/lilypond/current/}
3103 Within this directory the two interesting subdirectories are
3106 @item @file{../ly/ } - contains files in LilyPond format
3107 @item @file{../scm/} - contains files in Scheme format
3110 Let's begin by looking at some files in @file{../ly/}.
3111 Open @file{../ly/property-init.ly} in a text editor. The one
3112 you normally use for @code{.ly} files will be fine. This file
3113 contains the definitions of all the standard LilyPond built-in
3114 commands, such as @code{\stemUp} and @code{\slurDotted}. You will
3115 see that these are nothing more than definitions of variables
3116 containing one or a group of @code{\override} commands. For
3117 example, @code{/tieDotted} is defined to be:
3121 \override Tie #'dash-period = #0.75
3122 \override Tie #'dash-fraction = #0.1
3126 If you do not like the default values these built-in commands can
3127 be redefined easily, just like any other variable, at the
3128 head of your input file.
3130 The following are the most useful files to be found in
3133 @multitable @columnfractions .4 .6
3136 @item @file{../ly/engraver-init.ly}
3137 @tab Definitions of engraver Contexts
3138 @item @file{../ly/paper-defaults.ly}
3139 @tab Specifications of paper-related defaults
3140 @item @file{../ly/performer-init.ly}
3141 @tab Definitions of performer Contexts
3142 @item @file{../ly/property-init.ly}
3143 @tab Definitions of all common built-in commands
3146 Other settings (such as the definitions of markup commands) are
3147 stored as @code{.scm} (Scheme) files. The Scheme programming
3148 language is used to provide a programmable interface into
3149 LilyPond internal operation. Further explanation of these files
3150 is currently outside the scope of this manual, as a knowledge of
3151 the Scheme language is required. Users should be warned that
3152 a substantial amount of technical knowledge or time is required
3153 to understand Scheme and these files (see @ref{Scheme tutorial}).
3155 If you have this knowledge, the Scheme files which may be of
3158 @multitable @columnfractions .4 .6
3161 @item @file{../scm/auto-beam.scm}
3162 @tab Sub-beaming defaults
3163 @item @file{../scm/define-grobs.scm}
3164 @tab Default settings for grob properties
3165 @item @file{../scm/define-markup-commands.scm}
3166 @tab Specify all markup commands
3167 @item @file{../scm/midi.scm}
3168 @tab Default settings for MIDI output
3169 @item @file{../scm/output-lib.scm}
3170 @tab Settings that affect appearance of frets, colors,
3171 accidentals, bar lines, etc
3172 @item @file{../scm/parser-clef.scm}
3173 @tab Definitions of supported clefs
3174 @item @file{../scm/script.scm}
3175 @tab Default settings for articulations
3180 @node Avoiding tweaks with slower processing
3181 @subsection Avoiding tweaks with slower processing
3183 LilyPond can perform extra checks while it processes files. These
3184 checks will take extra time to perform, but fewer manual tweaks
3185 may be required to obtain an acceptable result. If a text script
3186 or part of the lyrics extends over the margins these checks will
3187 compress that line of the score just enough to fit within the
3190 To be effective under all circumstances these checks must be enabled
3191 by placing the overrides in a Score @code{\with} block, rather than
3192 in-line in music, as follows:
3196 % Makes sure text scripts and lyrics are within the paper margins
3197 \override PaperColumn #'keep-inside-line = ##t
3198 \override NonMusicalPaperColumn #'keep-inside-line = ##t
3204 @node Advanced tweaks with Scheme
3205 @subsection Advanced tweaks with Scheme
3207 Although many things are possible with the @code{\override} and
3208 @code{\tweak} commands, an even more powerful way of modifying
3209 the action of LilyPond is available through a programmable
3210 interface to the LilyPond internal operation. Code written in
3211 the Scheme programming language can be incorporated directly in
3212 the internal operation of LilyPond. Of course, at least a basic
3213 knowledge of programming in Scheme is required to do this, and an
3214 introduction is provided in the @ref{Scheme tutorial}.
3216 As an illustration of one of the many possibilities, instead of
3217 setting a property to a constant it can be set to a Scheme
3218 procedure which is then called whenever that property is accessed
3219 by LilyPond. The property can then be set dynamically to a value
3220 determined by the procedure at the time it is called. In this
3221 example we color the note head in accordance with its position on
3224 @lilypond[quote,verbatim,ragged-right]
3225 #(define (color-notehead grob)
3226 "Color the notehead according to its position on the staff."
3227 (let ((mod-position (modulo (ly:grob-property grob 'staff-position) 7)))
3229 ;; Return rainbow colors
3230 ((1) (x11-color 'red )) ; for C
3231 ((2) (x11-color 'orange )) ; for D
3232 ((3) (x11-color 'yellow )) ; for E
3233 ((4) (x11-color 'green )) ; for F
3234 ((5) (x11-color 'blue )) ; for G
3235 ((6) (x11-color 'purple )) ; for A
3236 ((0) (x11-color 'violet )) ; for B
3242 % Arrange to obtain color from color-notehead procedure
3243 \override NoteHead #'color = #color-notehead
3250 Some -- where o -- ver the Rain -- bow way up high,
3254 Further examples showing the use of these programmable interfaces
3255 can be found in @ref{Tweaking with Scheme}.