1.5.2 Multiple voices

This section discusses simultaneous notes in multiple voices or multiple staves.


Single-staff polyphony

Explicitly instantiating voices

The basic structure needed to achieve multiple independent voices in a single staff is illustrated in the following example:

\new Staff <<
  \new Voice = "first"
    { \voiceOne r8 r16 g e8. f16 g8[ c,] f e16 d }
  \new Voice= "second"
    { \voiceTwo d16 c d8~ d16 b c8~ c16 b c8~ c16 b8. }
>>

[image of music]

Here, voices are instantiated explicitly and are given names. The \voiceOne ... \voiceFour commands set up the voices so that first and third voices get stems up, second and fourth voices get stems down, third and fourth voice note heads are horizontally shifted, and rests in the respective voices are automatically moved to avoid collisions. The \oneVoice command returns all the voice settings to the neutral default directions.

Temporary polyphonic passages

A temporary polyphonic passage can be created with the following construct:

<< { \voiceOne ... }
  \new Voice { \voiceTwo ... }
>> \oneVoice

Here, the first expression within a temporary polyphonic passage is placed into the Voice context which was in use immediately before the polyphonic passage, and that same Voice context continues after the temporary section. Other expressions within the angle brackets are assigned to distinct temporary voices. This allows lyrics to be assigned to one continuing voice before, during and after a polyphonic section:

<<
  \new Voice = "melody" {
    a4
    <<
      {
        \voiceOne
        g f
      }
      \new Voice {
        \voiceTwo
        d2
      }
    >>
    \oneVoice
    e4
  }
  \new Lyrics \lyricsto "melody" {
  This is my song.
  }
>>

[image of music]

Here, the \voiceOne and \voiceTwo commands are required to define the settings of each voice.

The double backslash construct

The << {...} \\ {...} >> construct, where the two (or more) expressions are separated by double backslashes, behaves differently to the similar construct without the double backslashes: all the expressions within this contruct are assigned to new Voice contexts. These new Voice contexts are created implicitly and are given the fixed names "1", "2", etc.

The first example could be typeset as follows:

<<
  { r8 r16 g e8. f16 g8[ c,] f e16 d }
  \\
  { d16 c d8~ d16 b c8~ c16 b c8~ c16 b8. }
>>

[image of music]

This syntax can be used where it does not matter that temporary voices are created and then discarded. These implicitly created voices are given the settings equivalent to the effect of the \voiceOne ... \voiceFour commands, in the order in which they appear in the code.

In the following example, the intermediate voice has stems up, therefore we enter it in the third place, so it becomes voice three, which has the stems up as desired. Spacer rests are used to avoid printing doubled rests.

<<
  { r8 g g  g g f16 ees f8 d }
  \\
  { ees,8 r ees r d r d r }
  \\
  { d'8 s c s bes s a s }
>>

[image of music]

In all but the simplest works it is advisable to create explicit Voice contexts as explained in Contexts and engravers and Explicitly instantiating voices.

Identical rhythms

In the special case that we want to typeset parallel pieces of music that have the same rhythm, we can combine them into a single Voice context, thus forming chords. To achieve this, enclose them in a simple simultaneous music construct within an explicit voice:

\new Voice <<
  { e4 f8 d e16 f g8 d4 }
  { c4 d8 b c16 d e8 b4 }
>>

[image of music]

This method leads to strange beamings and warnings if the pieces of music do not have the same rhythm.

Predefined commands

\voiceOne, \voiceTwo, \voiceThree, \voiceFour, \oneVoice.

See also

Learning Manual: Voices contain music, Explicitly instantiating voices.

Notation Reference: Percussion staves, Invisible rests.

Snippets: Simultaneous notes.


Voice styles

Voices may be given distinct colors and shapes, allowing them to be easily identified:

<<
  { \voiceOneStyle d4 c2 b4 }
  \\
  { \voiceTwoStyle e,2 e }
  \\
  { \voiceThreeStyle b2. c4 }
  \\
  { \voiceFourStyle g'2 g }
>>

[image of music]

The \voiceNeutralstyle command is used to revert to the standard presentation.

Predefined commands

\voiceOneStyle, \voiceTwoStyle, \voiceThreeStyle, \voiceFourStyle, \voiceNeutralStyle.

See also

Learning Manual: I'm hearing Voices, Other sources of information.

Snippets: Simultaneous notes.


Collision resolution

The note heads of notes in different voices with the same pitch, same note head and opposite stem direction are automatically merged, but notes with different note heads or the same stem direction are not. Rests opposite a stem in a different voice are shifted vertically.

<<
  {
    c8 d e d c d c4
    g'2 fis
  } \\ {
    c2 c8. b16 c4
    e,2 r
  } \\ {
    \oneVoice
    s1
    e8 a b c d2
  }
>>

[image of music]

Notes with different note heads may be merged, with the exception of half-note heads and quarter-note heads:

<<
  {
    \mergeDifferentlyHeadedOn
    c8 d e d c d c4
    g'2 fis
  } \\ {
    c2 c8. b16 c4
    e,2 r
  } \\ {
    \oneVoice
    s1
    e8 a b c d2
  }
>>

[image of music]

Note heads with different dots may be merged:

<<
  {
    \mergeDifferentlyHeadedOn
    \mergeDifferentlyDottedOn
    c8 d e d c d c4
    g'2 fis
  } \\ {
    c2 c8. b16 c4
    e,2 r
  } \\ {
    \oneVoice
    s1
    e8 a b c d2
  }
>>

[image of music]

The half note and eighth note at the start of the second measure are incorrectly merged because \mergeDifferentlyHeadedOn cannot successfully complete the merge when three or more notes line up in the same column, and in this case a warning is given. To allow the merge to work properly a \shift must be applied to the note that should not be merged. Here, \shiftOn is applied to move the top g out of the column, and \mergeDifferentlyHeadedOn then works properly.

<<
  {
    \mergeDifferentlyHeadedOn
    \mergeDifferentlyDottedOn
    c8 d e d c d c4
    \shiftOn
    g'2 fis
  } \\ {
    c2 c8. b16 c4
    e,2 r
  } \\ {
    \oneVoice
    s1
    e8 a b c d2
  }

>>

[image of music]

The \shiftOn, \shiftOnn, and \shiftOnnn commands specify the degree to which chords of the current voice should be shifted. The outer voices (normally: voices one and two) have \shiftOff, while the inner voices (three and four) have \shiftOn. \shiftOnn and \shiftOnnn define further shift levels.

Notes are only merged if they have opposing stem directions (e.g. in Voice 1 and 2).

Predefined commands

\mergeDifferentlyDottedOn, \mergeDifferentlyDottedOff, \mergeDifferentlyHeadedOn, \mergeDifferentlyHeadedOff.

\shiftOn, \shiftOnn, \shiftOnnn, \shiftOff.

Selected Snippets

Additional voices to avoid collisions

In some instances of complex polyphonic music, additional voices are necessary to prevent collisions between notes. If more than four parallel voices are needed, additional voices can be added by defining a variable using the Scheme function context-spec-music.

voiceFive = #(context-spec-music (make-voice-props-set 4) 'Voice)
\relative c'' {
  \time 3/4 \key d \minor \partial 2
  <<
    { \voiceOne
      a4. a8
      e'4 e4. e8
      f4 d4. c8
    } \\ {
      \voiceThree
      f,2
      bes4 a2
      a4 s2
    } \\ {
      \voiceFive
      s2
      g4 g2
      f4 f2
    } \\ {
      \voiceTwo
      d2
      d4 cis2
      d4 bes2
    }
  >>
}

[image of music]

Forcing horizontal shift of notes

When the typesetting engine cannot cope, the following syntax can be used to override typesetting decisions. The units of measure used here are staff spaces.

\relative c' <<
  {
    <d g>2 <d g>
  }
  \\
  {
    <b f'>2
    \once \override NoteColumn #'force-hshift = #1.7
    <b f'>2
  }
>>

[image of music]

See also

Music Glossary: polyphony.

Learning Manual: Multiple notes at once, Voices contain music, Collisions of objects.

Snippets: Simultaneous notes.

Internals Reference: NoteColumn, NoteCollision, RestCollision.

Known issues and warnings

When using \mergeDifferentlyHeadedOn with an upstem eighth or a shorter note, and a downstem half note, the eighth note stem gets a slightly wrong offset because of the different width of the half note head symbol.

There is no support for chords where the same note occurs with different accidentals in the same chord. In this case, it is recommended to use enharmonic transcription, or to use special cluster notation (see Clusters).


Automatic part combining

Automatic part combining is used to merge two parts of music onto a staff. It is aimed at typesetting orchestral scores. When the two parts are identical for a period of time, only one is shown. In places where the two parts differ, they are typeset as separate voices, and stem directions are set automatically. Also, solo and a due parts are identified and marked by default.

The syntax for part combining is:

\partcombine musicexpr1 musicexpr2

The following example demonstrates the basic functionality of the part combiner: putting parts on one staff and setting stem directions and polyphony. The same variables are used for the independent parts and the combined staff.

instrumentOne = \relative c' {
  c4 d e f
  R1
  d'4 c b a
  b4 g2 f4
  e1
}

instrumentTwo = \relative g' {
  R1
  g4 a b c
  d c b a
  g f( e) d
  e1
}

<<
  \new Staff \instrumentOne
  \new Staff \instrumentTwo
  \new Staff \partcombine \instrumentOne \instrumentTwo
>>

[image of music]

The notes in the third measure appear only once, although they were specified in both parts. Stem, slur, and tie directions are set automatically, depending whether there is a solo or unison. When needed in polyphony situations, the first part (with context called one) always gets up stems, while the second (called two) always gets down stems. In solo situations, the first and second parts get marked with ‘Solo’ and ‘Solo II’, respectively. The unisono (a due) parts are marked by default with the text “a2”.

Both arguments to \partcombine will be interpreted as Voice contexts. If using relative octaves, \relative should be specified for both music expressions, i.e.,

\partcombine
  \relative … musicexpr1
  \relative … musicexpr2

A \relative section that is outside of \partcombine has no effect on the pitches of musicexpr1 and musicexpr2.

Selected Snippets

Combining two parts on the same staff

The part combiner tool ( \partcombine command ) allows the combination of several different parts on the same staff. Text directions such as "solo" or "a2" are added by default; to remove them, simply set the property printPartCombineTexts to "false". For vocal scores (hymns), there is no need to add "solo"/"a2" texts, so they should be switched off. However, it might be better not to use it if there are any solos, as they won’t be indicated. In such cases, standard polyphonic notation may be preferable.

This snippet presents the three ways two parts can be printed on a same staff: standard polyphony, \partcombine without texts, and \partcombine with texts.

musicUp = \relative c'' {
  \time 4/4
  a4 c4.( g8) a4 |
  g4 e' g,( a8 b) |
  c b a2.
}

musicDown = \relative c'' {
  g4 e4.( d8) c4 |
  r2 g'4( f8 e) |
  d2 \stemDown a
}

\score {
  <<
    <<
    \new Staff {
      \set Staff.instrumentName = "Standard polyphony  "
      << \musicUp \\ \musicDown >>
    }
    \new Staff \with { printPartCombineTexts = ##f } {
      \set Staff.instrumentName = "PartCombine without texts  "
      \partcombine \musicUp \musicDown
    }
    \new Staff {
      \set Staff.instrumentName = "PartCombine with texts  "
      \partcombine \musicUp \musicDown
    }
    >>
  >>
  \layout {
    indent = 6.0\cm
    \context {
      \Score
      \override SystemStartBar #'collapse-height = #30
    }
  }
}

[image of music]

Changing partcombine texts

When using the automatic part combining feature, the printed text for the solo and unison sections may be changed:

\new Staff <<
  \set Staff.soloText = #"girl"
  \set Staff.soloIIText = #"boy"
  \set Staff.aDueText = #"together"
  \partcombine
    \relative c'' {
      g4 g r r
      a2 g
    }
    \relative c'' {
      r4 r a( b)
      a2 g
    }
>>

[image of music]

See also

Music Glossary: a due, part.

Notation Reference: Writing parts.

Snippets: Simultaneous notes.

Internals Reference: PartCombineMusic, Voice.

Known issues and warnings

\partcombine can only accept two voices.

When printPartCombineTexts is set, if the two voices play the same notes on and off, the part combiner may typeset a2 more than once in a measure.

\partcombine cannot be inside \times.

\partcombine cannot be inside \relative.

Internally, the \partcombine interprets both arguments as Voices and decides when the parts can be combined. When they have different durations they cannot be combined and are given the names one and two. Consequently, if the arguments switch to differently named Voice contexts, the events in those will be ignored. Likewise, partcombining isn’t designed to work with lyrics; when one of the voices is explicitly named in order to attach lyrics to it, the partcombining stops working.

\partcombine only observes onset times of notes. It cannot determine whether a previously started note is playing or not, leading to various problems.


Writing music in parallel

Music for multiple parts can be interleaved in input code. The function \parallelMusic accepts a list with the names of a number of variables to be created, and a musical expression. The content of alternate measures from the expression become the value of the respective variables, so you can use them afterwards to print the music.

Note: Bar checks | must be used, and the measures must be of the same length.

\parallelMusic #'(voiceA voiceB voiceC) {
  % Bar 1
  r8 g'16 c'' e'' g' c'' e'' r8 g'16 c'' e'' g' c'' e'' |
  r16 e'8.~   e'4            r16 e'8.~   e'4            |
  c'2                        c'2                        |

  % Bar 2
  r8 a'16 d'' f'' a' d'' f'' r8 a'16 d'' f'' a' d'' f'' |
  r16 d'8.~   d'4            r16 d'8.~   d'4            |
  c'2                        c'2                        |

}
\new StaffGroup <<
  \new Staff << \voiceA \\ \voiceB >>
  \new Staff { \clef bass \voiceC }
>>

[image of music]

Relative mode may be used. Note that the \relative command is not used inside \parallelMusic itself. The notes are relative to the preceding note in the voice, not to the previous note in the input – in other words, relative notes for voiceA ignore the notes in voiceB.

\parallelMusic #'(voiceA voiceB voiceC) {
  % Bar 1
  r8 g16 c e g, c e r8 g,16 c e g, c e  |
  r16 e8.~ e4       r16 e8.~  e4        |
  c2                c                   |

  % Bar 2
  r8 a,16 d f a, d f r8 a,16 d f a, d f |
  r16 d8.~  d4       r16 d8.~  d4       |
  c2                 c                  |

 }
\new StaffGroup <<
  \new Staff << \relative c'' \voiceA \\ \relative c' \voiceB >>
  \new Staff \relative c' { \clef bass \voiceC }
>>

[image of music]

This works quite well for piano music. This example maps four consecutive measures to four variables:

global = {
  \key g \major
  \time 2/4
}

\parallelMusic #'(voiceA voiceB voiceC voiceD) {
  % Bar 1
  a8    b     c   d     |
  d4          e         |
  c16 d e fis d e fis g |
  a4          a         |

  % Bar 2
  e8      fis  g     a   |
  fis4         g         |
  e16 fis g  a fis g a b |
  a4           a         |

  % Bar 3 ...
}

\score {
  \new PianoStaff <<
     \new Staff {
       \global
       <<
         \relative c'' \voiceA
         \\
         \relative c'  \voiceB
       >>
     }
     \new Staff {
       \global \clef bass
       <<
         \relative c \voiceC
         \\
         \relative c \voiceD
       >>
     }
  >>
}

[image of music]

See also

Learning Manual: Organizing pieces with variables.

Snippets: Simultaneous notes.


Other languages: français, español, deutsch.

Notation Reference