### 1.6.2 Modifying single staves

This section explains how to change specific attributes of one staff: for example, modifying the number of staff lines or the staff size. Methods to start and stop staves and set ossia sections are also described.

#### Staff symbol

The \stopStaff and \startStaff commands can be used to stop or (re)start the staff lines respectively, from being printed at any point witin a score.

\relative {
\stopStaff f''4 d \startStaff g, e
f'4 d \stopStaff g, e
f'4 d \startStaff g, e
}


#### Predefined commands

\startStaff, \stopStaff.

The lines of a staff belong to the StaffSymbol grob (including ledger lines) and can be modified using StaffSymbol properties, but these modifications must be made before the staff is (re)started.

The number of staff lines can be altered:

\relative {
f''4 d \stopStaff
\override Staff.StaffSymbol.line-count = #2
\startStaff g, e |

f'4 d \stopStaff
\revert Staff.StaffSymbol.line-count
\startStaff g, e |
}


The position of each staff line can also be altered. A list of numbers sets each line’s position. 0 corresponds to the normal center line, and the normal line positions are (-4 -2 0 2 4). A single staff line is printed for every value entered so that the number of staff lines, as well as their position, can be changed with a single override (thus, the line-count property is disregarded if line-positions is set).

\relative {
f''4 d \stopStaff
\override Staff.StaffSymbol.line-positions = #'(1 3 5 -1 -3)
\startStaff g, e |
f'4 d \stopStaff
\override Staff.StaffSymbol.line-positions = #'(8 6.5 -6 -8 -0.5)
\startStaff g, e |
}


To preserve typical stem directions (in the bottom half of the staff stems point up, in the top half they point down), align the center line (or space) of the customized staff with the position of the normal center line (0). The clef position and the position of middle C may need to be adjusted accordingly to fit the new lines. See Clef.

Staff line thickness can be altered. Ledger lines and note stems, by default, are also affected.

\new Staff \with {
\override StaffSymbol.thickness = #3
} \relative {
f''4 d g, e
}


It is also possible to set ledger line thickness independently of staff lines.

\new Staff \with {
\override StaffSymbol.thickness = #2
\override StaffSymbol.ledger-line-thickness = #'(0.5 . 0.4)
} \relative {
f'''4 a, a,, f
}


The first value is multiplied by the staff line thickness, the second by the staff space and then the two values are added together to give the new thickness of the ledger line.

The vertical positions of ledger lines can be altered,

\new Staff \with {
\override StaffSymbol.ledger-positions = #'(-3 -2 -1 2 5 6)
} \relative {
f'''4 a, a,, f
}


Additional ledger lines can be made to appear above or below note heads depending on the current position relative to other note heads that also have their own ledger lines.

\new Staff \with {
\override StaffSymbol.ledger-extra = #4
} \relative {
f'''4 a, d, f,
}


Ledger lines can also be made to appear inside the staff where custom staff lines are required. The example shows the default position of ledger lines when the explicit ledger-position is and is not set. The \stopStaff is needed in the example to revert the \override for the whole StaffSymbol.

\relative d' {
\override Staff.StaffSymbol.line-positions = #'(-8 0 2 4)
d4 e f g
\stopStaff
\startStaff
\override Staff.StaffSymbol.ledger-positions = #'(-8 -6 (-4 -2) 0)
d4 e f g
}


The distance between staff lines can be altered. This affects ledger line spacing as well.

\new Staff \with {
\override StaffSymbol.staff-space = #1.5
} \relative {
f'''4 d, g, e,
}


The width of a staff can be modified. The units are staff spaces. The spacing of objects inside the staff is not affected by this setting.

\new Staff \with {
\override StaffSymbol.width = #23
}
\relative { a4 e' f b | d1 }


#### Making some staff lines thicker than the others

For educational purposes, a staff line can be thickened (e.g., the middle line, or to emphasize the line of the G clef). This can be achieved by adding extra lines very close to the line that should be emphasized, using the line-positions property of the StaffSymbol object.

{
\override Staff.StaffSymbol.line-positions =
#'(-4 -2 -0.2 0 0.2 2 4)
d'4 e' f' g'
}


Music Glossary: line, ledger line, staff.

Notation Reference: Clef.

Snippets: Staff notation.

Internals Reference: StaffSymbol, staff-symbol-interface.

#### Ossia staves

Ossia staves can be set by creating a new simultaneous staff in the appropriate location:

\new Staff \relative {
c''4 b d c
<<
{ c4 b d c }
\new Staff { e4 d f e }
>>
c4 b c2
}


However, the above example is not what is usually desired. To create ossia staves that are above the original staff, have no time signature or clef, and have a smaller font size, tweaks must be used. The Learning Manual describes a specific technique to achieve this goal, beginning with Nesting music expressions.

The following example uses the alignAboveContext property to align the ossia staff. This method is most appropriate when only a few ossia staves are needed.

\new Staff = "main" \relative {
c''4 b d c
<<
{ c4 b d c }

\new Staff \with {
\remove "Time_signature_engraver"
alignAboveContext = "main"
\magnifyStaff #2/3
firstClef = ##f
}
{ e4 d f e }
>>
c4 b c2
}


If many isolated ossia staves are needed, creating an empty Staff context with a specific context id may be more appropriate; the ossia staves may then be created by calling this context and using \startStaff and \stopStaff at the desired locations. The benefits of this method are more apparent if the piece is longer than the following example.

<<
\new Staff = "ossia" \with {
\remove "Time_signature_engraver"
\hide Clef
\magnifyStaff #2/3
}
{ \stopStaff s1*6 }

\new Staff \relative {
c'4 b c2
<<
{ e4 f e2 }
\context Staff = "ossia" {
\startStaff e4 g8 f e2 \stopStaff
}
>>
g4 a g2 \break
c4 b c2
<<
{ g4 a g2 }
\context Staff = "ossia" {
\startStaff g4 e8 f g2 \stopStaff
}
>>
e4 d c2
}
>>


Using the \RemoveAllEmptyStaves command to create ossia staves may be used as an alternative. This method is most convenient when ossia staves occur immediately following a line break. For more information about \RemoveAllEmptyStaves, see Hiding staves.

<<
\new Staff = "ossia" \with {
\remove "Time_signature_engraver"
\hide Clef
\magnifyStaff #2/3
\RemoveAllEmptyStaves
} \relative {
R1*3
c''4 e8 d c2
}
\new Staff \relative {
c'4 b c2
e4 f e2
g4 a g2 \break
c4 b c2
g4 a g2
e4 d c2
}
>>


#### Vertically aligning ossias and lyrics

This snippet demonstrates the use of the context properties alignBelowContext and alignAboveContext to control the positioning of lyrics and ossias.

\paper {
ragged-right = ##t
}

\relative c' <<
\new Staff = "1" { c4 c s2 }
\new Staff = "2" { c4 c s2 }
\new Staff = "3" { c4 c s2 }
{ \skip 2
<<
\lyrics {
\set alignBelowContext = #"1"
lyrics4 below
}
\new Staff \with {
alignAboveContext = #"3"
fontSize = #-2
\override StaffSymbol.staff-space = #(magstep -2)
\remove "Time_signature_engraver"
} {
\tuplet 6/4 {
c8[^"ossia above" d e d e f]
}
}
>>
}
>>


Music Glossary: ossia, staff, Frenched staff.

Learning Manual: Nesting music expressions, Size of objects, Length and thickness of objects.

Notation Reference: Hiding staves.

Snippets: Staff notation.

Internals Reference: StaffSymbol.

#### Hiding staves

Staff lines can be hidden by removing the Staff_symbol_engraver from the Staff context. As an alternative, \stopStaff may be used.

\new Staff \with {
\remove "Staff_symbol_engraver"
}
\relative { a''8 f e16 d c b a2 }


Empty staves can be hidden (for a so-called ‘Frenched Score’) by applying the \RemoveEmptyStaves command on a context, which can be done globally (in a \layout block) as well as for specific staves only (in a \with block). This command removes all empty staves in a score except for those in the first system. If you want those in the first system to be hidden also, use \RemoveAllEmptyStaves.

\layout {
\context {
\Staff
\RemoveEmptyStaves
}
}

\relative <<
\new Staff {
e'4 f g a \break
b1 \break
a4 b c2
}
\new Staff {
c,4 d e f \break
R1 \break
f4 g c,2
}
>>


A staff is considered empty when it contains only multi-measure rests, rests, skips, or a combination of these elements. All other musical objects (that cause a staff not to be considered as empty) are listed in the keepAliveInterfaces context property, as initially set in the ‘ly/engraver-init.ly’ file.

\RemoveEmptyStaves and \RemoveAllEmptyStaves are both predefined shortcuts that set such properties as remove-empty and remove-first for the VerticalAxisGroup object, as explained in Context modification identifiers.

The Keep_alive_together_engraver allows groups of staves to only be removed together and not individually. By default, it is part of the PianoStaff context: a piano part will only be hidden when both of its staves are empty. Similarly, a common engraving practice in orchestral scores is to remove empty groups of staves rather than individual staves; that can be achieved by adding the Keep_alive_together_engraver to the relevant staff grouping context, as explained Modifying context plug-ins (see Grouping staves for the context names).

\layout {
\context {
\StaffGroup
\RemoveEmptyStaves
\consists "Keep_alive_together_engraver"
}
}


In the following example, staves devoted to wind instruments are removed in the second system; however, the double bass is not, because it is part of the larger group of fretted strings, which is playing.

The Keep_alive_together_engraver internally uses the remove-layer property of a staff’s VerticalAxisGroup to decide whether to print it or not when it is considered empty. That property may also be set directly, in which case it acts as a priority index: values closest to zero take precedence over higher numbers, and thus staves whose remove-layer is higher will be masked in favor of staves of a lower number.

This is particularly useful for ‘divisi’ staves, where some individual parts (see Writing parts) occasionally need to be expanded to more than one staff. In the following example, two parts are routed to three staves; however, all three staves are never printed at the same time:

• in the first systems, only a single one of them is shown, as the keepAliveInterfaces property has been set to an empty list – therefore the other two staves are considered empty and thus hidden, regardless of what they may contain;
• when that property gets unset (and thus reverts to its default setting), it is no longer preventing the two other staves from being printed; however, as their remove-layer setting is lower than the single staff’s, these two staves are now printed in its place.

Such substitutions are applied not just to notes, chords and other musical events that occur immediately after the new setting, but to the whole system where it takes place.

\layout {
short-indent = 2\cm
indent = 3\cm
\context {
\Staff
keepAliveInterfaces = #'()
}
}

violI = {
\repeat unfold 24 { d'4 }
\once \unset Staff.keepAliveInterfaces
<d' g''>2
\repeat unfold 14 { d'4 }
\bar "|."
}

violII = {
\repeat unfold 24 { g4 }
<g d'>2
\repeat unfold 14 { g4 }
\bar "|."
}

\new StaffGroup \with { \consists "Keep_alive_together_engraver" } <<
\new Staff \with {
instrumentName = "Violins"
shortInstrumentName = "V I & II"
\override VerticalAxisGroup.remove-layer = 2
} <<  \violI \\ \violII  >>
\new Staff \with {
instrumentName = "Violin I"
shortInstrumentName = "V I"
\RemoveAllEmptyStaves
\override VerticalAxisGroup.remove-layer = 1
} \violI
\new Staff \with {
instrumentName = "Violin II"
shortInstrumentName = "V II"
\RemoveAllEmptyStaves
\override VerticalAxisGroup.remove-layer = 1
} \violII
>>


\RemoveAllEmptyStaves can also be used to create ossia sections for a staff. For details, see Ossia staves.

#### Predefined commands

\RemoveEmptyStaves, \RemoveAllEmptyStaves.

Music Glossary: Frenched staff.

Learning Manual: Visibility and color of objects.

Installed Files: ‘ly/engraver-init.ly’.

Snippets: Staff notation.

#### Known issues and warnings

Removing Staff_symbol_engraver also hides bar lines. If bar line visibility is forced, formatting errors may occur. In this case, use the following overrides instead of removing the engraver:

\omit StaffSymbol

For the Known issues and warnings associated with \RemoveEmptyStaves see Changing context default settings.