4.4 Placement of objects

4.4.1 Automatic behavior

There are some objects in musical notation that belong to the staff and there are other objects that should be placed outside the staff. These are called within-staff objects and outside-staff objects respectively.

Within-staff objects are those that are located on the staff – note heads, stems, accidentals, etc. The positions of these are usually fixed by the music itself – they are vertically positioned on specific lines of the staff or are tied to other objects that are so positioned. Collisions of note heads, stems and accidentals in closely set chords are normally avoided automatically. There are commands and overrides which can modify this automatic behavior, as we shall shortly see.

Objects belonging outside the staff include things such as rehearsal marks, text and dynamic markings. LilyPond’s rule for the vertical placement of outside-staff objects is to place them as close to the staff as possible but not so close that they collide with any other object. LilyPond uses the outside-staff-priority property to determine the order in which the objects should be placed, as follows.

First, LilyPond places all the within-staff objects. Then it sorts the outside-staff objects according to their outside-staff-priority. The outside-staff objects are taken one by one, beginning with the object with the lowest outside-staff-priority, and placed so that they do not collide with any objects that have already been placed. That is, if two outside-staff grobs are competing for the same space, the one with the lower outside-staff-priority will be placed closer to the staff. If two objects have the same outside-staff-priority the one encountered first will be placed closer to the staff.

In the following example all the markup texts have the same priority (since it is not explicitly set). Note that ‘Text3’ is automatically positioned close to the staff again, nestling under ‘Text2’.

c''2^"Text1" c''2^"Text2" | c''2^"Text3" c''2^"Text4" |

Staves are also positioned, by default, as closely together as possible (subject to a minimum separation). If notes project a long way towards an adjacent staff they will force the staves further apart only if an overlap of the notation would otherwise occur. The following example demonstrates this ‘nestling’ of the notes on adjacent staves:

<< \new Staff { \relative { c'4 a, } } \new Staff { \relative { c''''4 a, } } >>

4.4.2 Within-staff objects

We have already seen how the commands \voiceXXX affect the direction of slurs, ties, fingering and everything else which depends on the direction of the stems – see Explicitly instantiating voices. These commands are essential when writing polyphonic music to permit interweaving melodic lines to be distinguished. But occasionally it may be necessary to override this automatic behavior. This can be done for whole sections of music or even for an individual note. The property which controls this behavior is the direction property of each layout object. We first explain what this does, and then introduce a number of ready-made commands which avoid your having to code explicit overrides for the more common modifications.

Some layout objects like slurs and ties curve, bend or point either up or down; others like stems and flags also move to right or left when they point up or down. This is controlled automatically when direction is set.

The direction property

The following example shows in bar 1 the default behavior of stems, with those on high notes pointing down and those on low notes pointing up, followed by four notes with all stems forced down, four notes with all stems forced up, and finally four notes reverted back to the default behavior.

a4 g c a | \override Stem.direction = #DOWN a4 g c a | \override Stem.direction = #UP a4 g c a | \revert Stem.direction a4 g c a |

Here we use the constants DOWN and UP. These have the values -1 and +1 respectively, and these numerical values may be used instead. The value 0 may also be used in some cases. It is simply treated as meaning UP for stems, but for some objects it means ‘center’. There is a constant, CENTER which has the value 0.

However, these explicit overrides are not usually used, as there are simpler equivalent predefined commands available. Here is a table of the commonest. The meaning of each is stated where it is not obvious.

The neutral/normal variants of these commands are implemented using \revert and may not be preceded by \once. If you wish to limit the effect of the other commands (which are implemented using \override) to a single timestep, you can precede them with \once like you would do with explicit overrides.

Fingering

The placement of fingering on single notes can also be controlled by the direction property, but changing direction has no effect on chords. As we shall see, there are special commands which allow the fingering of individual notes of chords to be controlled, with the fingering being placed above, below, to the left or to the right of each note.

First, here’s the effect of direction on the fingering attached to single notes. The first bar shows the default behaviour, and the following two bars shows the effect of specifying DOWN and UP:

\relative { c''4-5 a-3 f-1 c'-5 | \override Fingering.direction = #DOWN c4-5 a-3 f-1 c'-5 | \override Fingering.direction = #UP c4-5 a-3 f-1 c'-5 | }

However, overriding the direction property is not the easiest way of manually setting the fingering above or below the notes; using _ or ^ instead of - before the fingering number is usually preferable. Here is the previous example using this method:

\relative { c''4-5 a-3 f-1 c'-5 | c4_5 a_3 f_1 c'_5 | c4^5 a^3 f^1 c'^5 | }

The direction property is ignored for chords, but the directional prefixes, _ and ^ do work. By default, the fingering is automatically placed both above and below the notes of a chord, as shown:

\relative { <c''-5 g-3>4 <c-5 g-3 e-2>4 <c-5 g-3 e-2 c-1>4 }

but this may be overridden to manually force all or any of the individual fingering numbers above or below:

\relative { <c''-5 g-3 e-2 c-1>4 <c^5 g_3 e_2 c_1>4 <c^5 g^3 e^2 c_1>4 }

Even greater control over the placement of fingering of the individual notes in a chord is possible by using the \set fingeringOrientations command. The format of this command is:

\set fingeringOrientations = #'([up] [left/right] [down])

\set is used because fingeringOrientations is a property of the Voice context, created and used by the New_fingering_engraver.

The property may be set to a list of one to three values. It controls whether fingerings may be placed above (if up appears in the list), below (if down appears), to the left (if left appears, or to the right (if right appears). Conversely, if a location is not listed, no fingering is placed there. LilyPond takes these constraints and works out the best placement for the fingering of the notes of the following chords. Note that left and right are mutually exclusive – fingering may be placed only on one side or the other, not both.

Here are a few examples:

\relative { \set fingeringOrientations = #'(left) <f'-2>4 <c-1 e-2 g-3 b-5>4 \set fingeringOrientations = #'(left) <f-2>4 <c-1 e-2 g-3 b-5>4 | \set fingeringOrientations = #'(up left down) <f-2>4 <c-1 e-2 g-3 b-5>4 \set fingeringOrientations = #'(up left) <f-2>4 <c-1 e-2 g-3 b-5>4 | \set fingeringOrientations = #'(right) <f-2>4 <c-1 e-2 g-3 b-5>4 }

If the fingering seems a little crowded the font-size could be reduced. The default value can be seen from the Fingering object in the IR to be -5, so let’s try -7:

\relative { \override Fingering.font-size = #-7 \set fingeringOrientations = #'(left) <f'-2>4 <c-1 e-2 g-3 b-5>4 \set fingeringOrientations = #'(left) <f-2>4 <c-1 e-2 g-3 b-5>4 | \set fingeringOrientations = #'(up left down) <f-2>4 <c-1 e-2 g-3 b-5>4 \set fingeringOrientations = #'(up left) <f-2>4 <c-1 e-2 g-3 b-5>4 | \set fingeringOrientations = #'(right) <f-2>4 <c-1 e-2 g-3 b-5>4 }

4.4.3 Outside-staff objects

Outside-staff objects are automatically placed to avoid collisions. There are several ways to override the automatic placement if the positioning is not optimum.

The outside-staff-priority property

Objects with the lower value of the outside-staff-priority property are placed nearer to the staff, and other outside-staff objects are then raised as far as necessary to avoid collisions. The outside-staff-priority is defined in the grob-interface and so is a property of all layout objects. By default it is set to #f for all within-staff objects, and to a numerical value appropriate to each outside-staff object when the object is created. The following table shows the default numerical values for some of the commonest outside-staff objects.

Note the unusual names for some of the objects: spanner objects are automatically created to control the vertical positioning of grobs which (might) start and end at different musical moments, so changing the outside-staff-priority of the underlying grob will have no effect. For example, changing outside-staff-priority of the Hairpin object will have no effect on the vertical positioning of hairpins – you must change outside-staff-priority of the associated DynamicLineSpanner object instead. This override must be placed at the start of the spanner, which might include several linked hairpins and dynamics.

Here is an example showing the default placement of some of these.

% Set details for later Text Spanner \override TextSpanner.bound-details.left.text = \markup { \small \bold Slower } % Place dynamics above staff \dynamicUp % Start Ottava Bracket \ottava #1 c''4 \startTextSpan % Add Dynamic Text and hairpin c''4\pp\< c''4 % Add Text Script c''4^Text | c''4 c'' % Add Dynamic Text and terminate hairpin c''4\ff c'' \stopTextSpan | % Stop Ottava Bracket \ottava #0 c'4 c' c' c' |

This example also shows how to create Text Spanners – text with extender lines above a section of music. The spanner extends from the \startTextSpan command to the \stopTextSpan command, and the format of the text is defined by the \override TextSpanner command. For more details see (notation)Text spanners section ‘Text spanners’ in Notatie-handleiding.

It also shows how ottava brackets are created.

If the default values of outside-staff-priority do not give you the placing you want, the priority of any of the objects may be overridden. Suppose we would like the ottava bracket to be placed below the text spanner in the example above. All we need to do is to look up the priority of OttavaBracket in the IR or in the tables above, and reduce it to a value lower than that of a TextSpanner, remembering that OttavaBracket is created in the Staff context:

% Set details for later Text Spanner \override TextSpanner.bound-details.left.text = \markup { \small \bold Slower } % Place dynamics above staff \dynamicUp % Place following Ottava Bracket below Text Spanners \once \override Staff.OttavaBracket.outside-staff-priority = #340 % Start Ottava Bracket \ottava #1 c''4 \startTextSpan % Add Dynamic Text c''4\pp % Add Dynamic Line Spanner c''4\< % Add Text Script c''4^Text | c''4 c'' % Add Dynamic Text c''4\ff c'' \stopTextSpan | % Stop Ottava Bracket \ottava #0 c'4 c' c' c' |

Note that some of these objects, in particular bar numbers, metronome marks and rehearsal marks, live by default in the Score context, so be sure to use the correct context when these are being overriden.

Slurs by default are classed as within-staff objects, but they often appear above the staff if the notes to which they are attached are high on the staff. This can push outside-staff objects such as articulations too high, as the slur will be placed first. The avoid-slur property of the articulation can be set to 'inside to bring the articulation inside the slur, but the avoid-slur property is effective only if the outside-staff-priority is also set to #f. Alternatively, the outside-staff-priority of the slur can be set to a numerical value to cause it to be placed along with other outside-staff objects according to that value. Here’s an example showing the effect of the two methods:

\relative c'' { c4( c^\markup { \tiny \sharp } d4.) c8 | c4( \once \override TextScript.avoid-slur = #'inside \once \override TextScript.outside-staff-priority = ##f c4^\markup { \tiny \sharp } d4.) c8 | \once \override Slur.outside-staff-priority = #500 c4( c^\markup { \tiny \sharp } d4.) c8 | }

Changing the outside-staff-priority can also be used to control the vertical placement of individual objects, although the results may not always be desirable. Suppose we would like “Text3” to be placed above “Text4” in the example under Automatic behavior, above (see Automatic behavior). All we need to do is to look up the priority of TextScript in the IR or in the tables above, and increase the priority of “Text3” to a higher value:

c''2^"Text1" c''2^"Text2" | \once \override TextScript.outside-staff-priority = #500 c''2^"Text3" c''2^"Text4" |

This certainly lifts “Text3” above “Text4” but it also lifts it above “Text2”, and “Text4” now drops down. Perhaps this is not so good. What we would really like to do is to position all the annotation at the same distance above the staff. To do this, we clearly will need to space the notes out horizontally to make more room for the text. This is done using the textLengthOn command.

The \textLengthOn command

By default, text produced by markup takes up no horizontal space as far as laying out the music is concerned. The \textLengthOn command reverses this behavior, causing the notes to be spaced out as far as is necessary to accommodate the text:

\textLengthOn % Cause notes to space out to accommodate text c''2^"Text1" c''2^"Text2" | c''2^"Text3" c''2^"Text4" |

The command to revert to the default behavior is \textLengthOff. Remember \once only works with \override, \set, \revert or \unset, so cannot be used with \textLengthOn.

Markup text will also avoid notes which project above the staff. If this is not desired, the automatic displacement upwards may be turned off by setting the priority to #f. Here’s an example to show how markup text interacts with such notes.

\relative { % This markup is short enough to fit without collision c''2^"Tex" c'' | R1 | % This is too long to fit, so it is displaced upwards c,,2^"Text" c'' | R1 | % Turn off collision avoidance \once \override TextScript.outside-staff-priority = ##f c,,2^"Long Text " c'' | R1 | % Turn off collision avoidance \once \override TextScript.outside-staff-priority = ##f \textLengthOn % and turn on textLengthOn c,,2^"Long Text " % Spaces at end are honored c''2 | }

Dynamics placement

Dynamic markings will normally be positioned beneath the staff, but may be positioned above with the \dynamicUp command. They will be positioned vertically relative to the note to which they are attached, and will float below (or above) all within-staff objects such as phrasing slurs and bar numbers. This can give quite acceptable results, as this example shows:

\relative { \clef "bass" \key aes \major \time 9/8 \dynamicUp bes4.~\f\< \( bes4 bes8 des4\ff\> c16 bes\! | ees,2.~\)\mf ees4 r8 | }

However, if the notes and attached dynamics are close together the automatic placement will avoid collisions by displacing later dynamic markings further away, but this may not be the optimum placement, as this rather artificial example shows:

\dynamicUp a4\f b\mf c\mp b\p

Should a similar situation arise in ‘real’ music, it may be preferable to space out the notes a little further, so the dynamic markings can all fit at the same vertical distance from the staff. We were able to do this for markup text by using the \textLengthOn command, but there is no equivalent command for dynamic marks. So we shall have to work out how to do this using \override commands.

Grob sizing

First we must learn how grobs are sized. All grobs have a reference point defined within them which is used to position them relative to their parent object. This point in the grob is then positioned at a horizontal distance, X-offset, and at a vertical distance, Y-offset, from its parent. The horizontal extent of the object is given by a pair of numbers, X-extent, which say where the left and right edges are relative to the reference point. The vertical extent is similarly defined by a pair of numbers, Y-extent. These are properties of all grobs which support the grob-interface.

By default, outside-staff objects are given a width of zero so that they may overlap in the horizontal direction. This is done by the trick of adding infinity to the leftmost extent and minus infinity to the rightmost extent by setting the extra-spacing-width to '(+inf.0 . -inf.0). So to ensure they do not overlap in the horizontal direction we must override this value of extra-spacing-width to '(0 . 0) so the true width shines through. This is the command to do this for dynamic text:

\override DynamicText.extra-spacing-width = #'(0 . 0)

Let’s see if this works in our previous example:

\dynamicUp \override DynamicText.extra-spacing-width = #'(0 . 0) a4\f b\mf c\mp b\p |

Well, it has certainly stopped the dynamic marks being displaced, but two problems remain. The marks should be spaced a little further apart and it would be better if they were all the same distance from the staff. We can solve the first problem easily. Instead of making the extra-spacing-width zero we could add a little more to it. The units are the space between two staff lines, so moving the left edge half a unit to the left and the right edge half a unit to the right should do it:

\dynamicUp % Extend width by 1 staff space \override DynamicText.extra-spacing-width = #'(-0.5 . 0.5) a4\f b\mf c\mp b\p

This looks better, but maybe we would prefer the dynamic marks to be aligned along the same baseline rather than going up and down with the notes. The property to do this is staff-padding which is covered in the following section.

This document was generated by gub on Juli 13, 2020 using texi2html 1.82.

Andere talen: English, català, česky, deutsch, español, français, italiano, 日本語.
Gebruik van automatische taalkeuze.