--- /dev/null
+@c -*- coding: utf-8; mode: texinfo; -*-
+@ignore
+ Translation of GIT committish: FILL-IN-HEAD-COMMITTISH
+
+ When revising a translation, copy the HEAD committish of the
+ version that you are working on. For details, see the Contributors'
+ Guide, node Updating translation committishes..
+@end ignore
+
+@c \version "2.14.0"
+
+
+@node Simultaneous notes
+@section Simultaneous notes
+
+@lilypondfile[quote]{simultaneous-headword.ly}
+
+Polyphony in music refers to having more than one voice occurring
+in a piece of music. Polyphony in LilyPond refers to having more
+than one voice on the same staff.
+
+@menu
+* Single voice::
+* Multiple voices::
+@end menu
+
+
+@node Single voice
+@subsection Single voice
+
+This section discusses simultaneous notes inside the same voice.
+
+@menu
+* Chorded notes::
+* Chord repetition::
+* Simultaneous expressions::
+* Clusters::
+@end menu
+
+
+@node Chorded notes
+@unnumberedsubsubsec Chorded notes
+
+@cindex chords
+@cindex brackets, angle
+
+@funindex <
+@funindex >
+@funindex <...>
+
+A chord is formed by enclosing a set of pitches between @code{<}
+and @code{>}. A chord may be followed by a duration just like simple
+notes.
+
+@lilypond[verbatim,quote,relative=2]
+<a c e>1 <a c e>2 <f a c e>4 <a c>8. <g c e>16
+@end lilypond
+
+Chords may also be followed by articulations, again just like simple
+notes.
+
+@lilypond[verbatim,quote,relative=2]
+<a c e>1\fermata <a c e>2-> <f a c e>4\prall <a c>8.^| <g c e>16-.
+@end lilypond
+
+The notes within the chord themselves can also be followed by articulation
+and ornamentation.
+
+@lilypond[verbatim,quote,relative=2]
+<a c\prall e>1 <a-> c-^ e>2 <f-. a c-. e-.>4 <a-+ c-->8. <g\fermata c e\turn>16
+@end lilypond
+
+However some notation, such as dynamics, hairpins and slurs must be
+attached to the chord, rather than notes within the chord, otherwise
+they will not print.
+
+@lilypond[verbatim,quote,relative=2]
+<a\f c( e>1 <a c) e>\f <a\< c e>( <a\! c e>) <a c e>\< <a c e> <a c e>\!
+@end lilypond
+
+@cindex relative pitch, chords
+@cindex chords, relative pitch
+
+Relative mode can be used for pitches in chords. The first note of
+each chord is always relative to the first note of the chord that
+came before it, or in the case where no preceding chord exists, the
+pitch of the last note that came before the chord. All remaining notes
+in the chord are relative to the note that came before it
+@emph{within the same chord}.
+
+@lilypond[verbatim,quote,relative=2]
+<a c e>1 <f a c> <a c e> <f' a c> <b, e b,>
+@end lilypond
+
+For more information about chords, see @ref{Chord notation}.
+
+@seealso
+Music Glossary:
+@rglos{chord}.
+
+Learning Manual:
+@rlearning{Combining notes into chords}.
+
+Notation Reference:
+@ref{Chord notation},
+@ref{Articulations and ornamentations},
+@ref{Relative octave entry},
+@ref{Multiple voices}.
+
+Snippets:
+@rlsr{Simultaneous notes}.
+
+@knownissues
+Chords containing more than two pitches within a staff space,
+such as @samp{<e f! fis!>}, create overlapping noteheads.
+Depending on the situation, better representations might involve
+
+@itemize
+
+@item
+temporary use of @ref{Multiple voices},
+@samp{<< f! \\ <e fis!> >>},
+
+@item
+enharmonic transcription of one or more pitches,
+@samp{<e f ges>}, or
+
+@item
+@ref{Clusters}.
+
+@end itemize
+
+@node Chord repetition
+@unnumberedsubsubsec Chord repetition
+
+In order to save typing, a shortcut can be used to repeat the preceding
+chord. The chord repetition symbol is @code{q}:
+
+@lilypond[verbatim,quote,relative=2]
+<a c e>1 q <f a c>2 q
+@end lilypond
+
+As with regular chords, the chord repetition symbol can be used with
+durations, articulations, markups, slurs, beams, etc. as only the
+pitches of the previous chord are duplicated.
+
+@lilypond[verbatim,quote,relative=2]
+<a c e>1\p^"text" q2\<( q8)[-| q8.]\! q16-1-2-3 q8\prall
+@end lilypond
+
+The chord repetition symbol always remembers the last instance of
+a chord so it is possible to repeat the most recent chord even if
+other non-chorded notes or rests have been added since.
+
+@lilypond[verbatim,quote,relative=2]
+<a c e>1 c4 q2 r8 q8
+@end lilypond
+
+However, the chord repetition symbol does not retain any dynamics,
+articulation or ornamentation within, or attached to the previous chord.
+
+@lilypond[verbatim,quote,relative=2]
+<a-. c\prall e>1\sfz c4 q2 r8 q8
+@end lilypond
+
+@seealso
+Notation Reference:
+@ref{Chord notation},
+@ref{Articulations and ornamentations}.
+
+Installed Files:
+@file{ly/chord-repetition-init.ly}.
+
+
+@node Simultaneous expressions
+@unnumberedsubsubsec Simultaneous expressions
+
+One or more music expressions enclosed in double angle brackets are
+taken to be simultaneous. If the first expression begins with a
+single note or if the whole simultaneous expression appears
+explicitly within a single voice, the whole expression is placed on
+a single staff; otherwise the elements of the simultaneous
+expression are placed on separate staves.
+
+The following examples show simultaneous expressions on one staff:
+
+@lilypond[quote,verbatim,relative=2]
+\new Voice { % explicit single voice
+ << { a4 b g2 } { d4 g c,2 } >>
+}
+@end lilypond
+
+@lilypond[quote,verbatim,relative=2]
+% single first note
+a << { a4 b g } { d4 g c, } >>
+@end lilypond
+
+This can be useful if the simultaneous sections have identical
+rhythms, but attempts to attach notes with different durations
+to the same stem will cause errors.
+
+The following example shows how simultaneous expressions can
+generate multiple staves implicitly:
+
+@lilypond[quote,verbatim,relative=2]
+% no single first note
+<< { a4 b g2 } { d4 g2 c,4 } >>
+@end lilypond
+
+Here different rhythms cause no problems.
+
+
+@node Clusters
+@unnumberedsubsubsec Clusters
+
+@cindex cluster
+@cindex note cluster
+
+@funindex \makeClusters
+@funindex makeClusters
+
+A cluster indicates a continuous range of pitches to be played.
+They can be denoted as the envelope of a set of notes. They are
+entered by applying the function @code{\makeClusters} to a sequence
+of chords, e.g.,
+
+@lilypond[quote,relative=2,verbatim]
+\makeClusters { <g b>2 <c g'> }
+@end lilypond
+
+Ordinary notes and clusters can be put together in the same staff,
+even simultaneously. In such a case no attempt is made to
+automatically avoid collisions between ordinary notes and clusters.
+
+
+@seealso
+Music Glossary:
+@rglos{cluster}.
+
+Snippets:
+@rlsr{Simultaneous notes}.
+
+Internals Reference:
+@rinternals{ClusterSpanner},
+@rinternals{ClusterSpannerBeacon},
+@rinternals{Cluster_spanner_engraver}.
+
+
+@knownissues
+
+Clusters look good only if they span at least two chords; otherwise
+they appear too narrow.
+
+Clusters do not have a stem and cannot indicate durations by
+themselves, but the length of the printed cluster is determined by
+the durations of the defining chords. Separate clusters need a
+separating rest between them.
+
+Clusters do not produce MIDI output.
+
+@node Multiple voices
+@subsection Multiple voices
+
+This section discusses simultaneous notes in multiple voices or
+multiple staves.
+
+@menu
+* Single-staff polyphony::
+* Voice styles::
+* Collision resolution::
+* Automatic part combining::
+* Writing music in parallel::
+@end menu
+
+
+@node Single-staff polyphony
+@unnumberedsubsubsec Single-staff polyphony
+
+@cindex single-staff polyphony
+@cindex polyphony, single-staff
+@cindex voice
+@cindex lyrics assigned to one voice
+
+@funindex \voiceOne
+@funindex voiceOne
+@funindex \voiceOne ... \voiceFour
+@funindex Voice
+@funindex \oneVoice
+@funindex oneVoice
+
+@strong{@i{Explicitly instantiating voices}}
+
+The basic structure needed to achieve multiple independent
+voices in a single staff is illustrated in the following example:
+
+@lilypond[quote,relative=3,verbatim]
+\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. }
+>>
+@end lilypond
+
+@noindent
+Here, voices are instantiated explicitly and are given names. The
+@code{\voiceOne} ... @code{\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 @code{\oneVoice}
+command returns all the voice settings to the neutral default
+directions.
+
+@strong{@i{Temporary polyphonic passages}}
+
+A temporary polyphonic passage can be created with the following
+construct:
+
+@example
+<< @{ \voiceOne ... @}
+ \new Voice @{ \voiceTwo ... @}
+>> \oneVoice
+@end example
+
+@noindent
+Here, the first expression within a temporary polyphonic passage is
+placed into the @code{Voice} context which was in use immediately
+before the polyphonic passage, and that same @code{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:
+
+@lilypond[quote, verbatim, relative=2]
+<<
+ \new Voice = "melody" {
+ a4
+ <<
+ {
+ \voiceOne
+ g f
+ }
+ \new Voice {
+ \voiceTwo
+ d2
+ }
+ >>
+ \oneVoice
+ e4
+ }
+ \new Lyrics \lyricsto "melody" {
+ This is my song.
+ }
+>>
+@end lilypond
+
+@noindent
+Here, the @code{\voiceOne} and @code{\voiceTwo} commands are
+required to define the settings of each voice.
+
+@strong{@i{The double backslash construct}}
+
+The @code{<< @{...@} \\ @{...@} >>} construct, where the two (or
+more) expressions are separated by double backslashes, behaves
+differently to the similar construct without the double backslashes:
+@emph{all} the expressions within this construct are assigned
+to new @code{Voice} contexts. These new @code{Voice} contexts
+are created implicitly and are given the fixed names @code{"1"},
+@code{"2"}, etc.
+
+The first example could be typeset as follows:
+
+@lilypond[quote,relative=3,verbatim]
+<<
+ { r8 r16 g e8. f16 g8[ c,] f e16 d }
+ \\
+ { d16 c d8~ d16 b c8~ c16 b c8~ c16 b8. }
+>>
+@end lilypond
+
+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
+@code{\voiceOne} ... @code{\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.
+
+@lilypond[quote,relative=3,verbatim]
+<<
+ { 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 }
+>>
+@end lilypond
+
+In all but the simplest works it is advisable to create explicit
+@code{Voice} contexts as explained in @rlearning{Contexts and engravers} and
+@rlearning{Explicitly instantiating voices}.
+
+@strong{@i{Voice order}}
+
+When entering multiple voices in the input file, use the following
+order:
+
+@example
+Voice 1: highest
+Voice 2: lowest
+Voice 3: second highest
+Voice 4: second lowest
+Voice 5: third highest
+Voice 6: third lowest
+etc.
+@end example
+
+Though this may seem counterintuitive, it simplifies the automatic
+layout process. Note that the odd-numbered voices are given
+upstems, and the even-numbered voices are given downstems:
+
+@lilypond[quote,verbatim]
+\new Staff <<
+ \time 2/4
+ { f''2 } % 1: highest
+ \\
+ { c'2 } % 2: lowest
+ \\
+ { d''2 } % 3: second-highest
+ \\
+ { e'2 } % 4: second-lowest
+ \\
+ { b'2 } % 5: third-highest
+ \\
+ { g'2 } % 6: third-lowest
+>>
+@end lilypond
+
+@strong{@i{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
+@code{Voice} context, thus forming chords. To achieve this, enclose
+them in a simple simultaneous music construct within an explicit voice:
+
+@lilypond[quote,relative=2,verbatim]
+\new Voice <<
+ { e4 f8 d e16 f g8 d4 }
+ { c4 d8 b c16 d e8 b4 }
+>>
+@end lilypond
+
+This method leads to strange beamings and warnings if the pieces of
+music do not have the same rhythm.
+
+
+@predefined
+@code{\voiceOne},
+@code{\voiceTwo},
+@code{\voiceThree},
+@code{\voiceFour},
+@code{\oneVoice}.
+@endpredefined
+
+
+@seealso
+Learning Manual:
+@rlearning{Voices contain music},
+@rlearning{Explicitly instantiating voices}.
+
+Notation Reference:
+@ref{Percussion staves},
+@ref{Invisible rests},
+@ref{Stems}.
+
+Snippets:
+@rlsr{Simultaneous notes}.
+
+
+@node Voice styles
+@unnumberedsubsubsec Voice styles
+
+@cindex voice styles
+@cindex styles, voice
+@cindex coloring voices
+@funindex \voiceOneStyle
+@funindex \voiceTwoStyle
+@funindex \voiceThreeStyle
+@funindex \voiceFourStyle
+@funindex \voiceNeutralStyle
+
+Voices may be given distinct colors and shapes, allowing them to be
+easily identified:
+
+@lilypond[quote,relative=2,verbatim]
+<<
+ { \voiceOneStyle d4 c2 b4 }
+ \\
+ { \voiceTwoStyle e,2 e }
+ \\
+ { \voiceThreeStyle b2. c4 }
+ \\
+ { \voiceFourStyle g'2 g }
+>>
+@end lilypond
+
+The @code{\voiceNeutralStyle} command is used to revert to the
+standard presentation.
+
+
+@predefined
+@code{\voiceOneStyle},
+@code{\voiceTwoStyle},
+@code{\voiceThreeStyle},
+@code{\voiceFourStyle},
+@code{\voiceNeutralStyle}.
+@endpredefined
+
+
+@seealso
+Learning Manual:
+@rlearning{I'm hearing Voices},
+@rlearning{Other sources of information}.
+
+Snippets:
+@rlsr{Simultaneous notes}.
+
+
+@node Collision resolution
+@unnumberedsubsubsec Collision resolution
+
+@cindex merging notes
+@cindex note collisions
+@cindex collisions
+@cindex shift note
+@cindex multiple voices
+@cindex voices, multiple
+@cindex polyphonic music
+@cindex shifting voices
+@cindex voices, multiple
+@cindex shift rest, automatic
+@funindex \shiftOn
+@funindex shiftOn
+@funindex \shiftOnn
+@funindex shiftOnn
+@funindex \shiftOnnn
+@funindex shiftOnnn
+@funindex \shiftOff
+@funindex shiftOff
+@funindex \mergeDifferentlyDottedOn
+@funindex mergeDifferentlyDottedOn
+@funindex \mergeDifferentlyDottedOff
+@funindex mergeDifferentlyDottedOff
+@funindex \mergeDifferentlyHeadedOn
+@funindex mergeDifferentlyHeadedOn
+@funindex \mergeDifferentlyHeadedOff
+@funindex mergeDifferentlyHeadedOff
+
+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. The following example shows three
+different circumstances, on beats 1 and 3 in bar 1 and beat 1
+in bar 2, where the automatic merging fails.
+
+@lilypond[quote,verbatim,relative=2]
+<<
+ {
+ c8 d e d c d c4
+ g'2 fis
+ } \\ {
+ c2 c8. b16 c4
+ e,2 r
+ } \\ {
+ \oneVoice
+ s1
+ e8 a b c d2
+ }
+>>
+@end lilypond
+
+Notes with different note heads may be merged, with the
+exception of half-note heads and quarter-note heads, as shown
+below. Here the note heads on beat 1 of bar 1 are now merged:
+
+@lilypond[quote,verbatim,relative=2]
+<<
+ {
+ \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
+ }
+>>
+@end lilypond
+
+Note heads with different dots as shown in beat 3 of bar 1 may be
+also be merged:
+
+@lilypond[quote,relative=2,verbatim]
+<<
+ {
+ \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
+ }
+>>
+@end lilypond
+
+
+The half note and eighth note at the start of the second measure
+are incorrectly merged because the automatic merge cannot
+successfully complete the merge when three or more notes line up in
+the same note column, and in this case the merged note head is
+incorrect. To allow the merge to select the correct note head
+a @code{\shift} must be applied to the note that should not be
+merged. Here, @code{\shiftOn} is applied to move the top
+@notation{g} out of the column, and @code{\mergeDifferentlyHeadedOn}
+then works properly.
+
+@lilypond[quote,relative=2,verbatim]
+<<
+ {
+ \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
+ }
+>>
+@end lilypond
+
+The @code{\shiftOn} command allows (but does not force) the notes
+in a voice to be shifted. When @code{\shiftOn} is applied to a
+voice, a note or chord in that voice is shifted only if its stem
+would otherwise collide with a stem from another voice, and only
+if the colliding stems point in the same direction. The
+@code{\shiftOff} command prevents this type of shifting from
+occurring.
+
+By default, the outer voices (normally voices one and two) have
+@code{\shiftOff} specified, while the inner voices (three and
+above) have @code{\shiftOn} specified. When a shift is applied,
+voices with upstems (odd-numbered voices) are shifted to the
+right, and voices with downstems (even-numbered voices) are
+shifted to the left.
+
+Here is an example to help you visualize how an abbreviated
+polyphonic expression would be expanded internally.
+
+@warning{Note that with three or more voices, the vertical order
+of voices in your input file should not be the same as the
+vertical order of voices on the staff!}
+
+@lilypond[quote,verbatim]
+\new Staff \relative c'' {
+ %% abbreviated entry
+ <<
+ { f2 } % 1: highest
+ \\
+ { g,2 } % 2: lowest
+ \\
+ { d'2 } % 3: upper middle
+ \\
+ { b2 } % 4: lower middle
+ >>
+ %% internal expansion of the above
+ <<
+ \new Voice = "1" { \voiceOne \shiftOff f'2 }
+ \new Voice = "2" { \voiceTwo \shiftOff g,2 }
+ \new Voice = "3" { \voiceThree \shiftOn d'2 } % shifts right
+ \new Voice = "4" { \voiceFour \shiftOn b2 } % shifts left
+ >>
+}
+@end lilypond
+
+Two additional commands, @code{\shiftOnn} and @code{\shiftOnnn}
+provide further shift levels which may be specified temporarily to
+resolve collisions in complex situations -- see
+@rlearning{Real music example}.
+
+Notes are only merged if they have opposing stem directions (as
+they have, for example, in voices one and two by default or when
+the stems are explicitly set in opposite directions).
+
+
+@predefined
+@code{\mergeDifferentlyDottedOn},
+@code{\mergeDifferentlyDottedOff},
+@code{\mergeDifferentlyHeadedOn},
+@code{\mergeDifferentlyHeadedOff}.
+
+@code{\shiftOn},
+@code{\shiftOnn},
+@code{\shiftOnnn},
+@code{\shiftOff}.
+@endpredefined
+
+
+@snippets
+
+@lilypondfile[verbatim,lilyquote,texidoc,doctitle]
+{additional-voices-to-avoid-collisions.ly}
+
+@lilypondfile[verbatim,lilyquote,texidoc,doctitle]
+{forcing-horizontal-shift-of-notes.ly}
+
+
+@seealso
+Music Glossary:
+@rglos{polyphony}.
+
+Learning Manual:
+@rlearning{Multiple notes at once},
+@rlearning{Voices contain music},
+@rlearning{Real music example}.
+
+Snippets:
+@rlsr{Simultaneous notes}.
+
+Internals Reference:
+@rinternals{NoteColumn},
+@rinternals{NoteCollision},
+@rinternals{RestCollision}.
+
+
+@ignore
+@knownissues
+@c TODO investigate! Sometimes it works, sometimes not. --FV
+The requirements for successfully merging different note heads that
+are at the same time differently dotted are not clear.
+@end ignore
+
+@node Automatic part combining
+@unnumberedsubsubsec Automatic part combining
+
+@cindex automatic part combining
+@cindex part combiner
+@cindex combining parts
+@cindex a due part
+@cindex solo part
+@funindex \partcombine
+@funindex partcombine
+
+Automatic part combining is used to merge two separate parts of music
+onto a single staff. This can be especially helpful when typesetting
+orchestral scores. A single @code{Voice} is printed while the two parts
+of music are the same, but in places where they differ, a second
+@code{Voice} is printed. Stem directions are set up & down accordingly
+while Solo and @notation{a due} parts are also identified and marked
+appropriately.
+
+The syntax for automatic part combining is:
+
+@example
+\partcombine @var{musicexpr1} @var{musicexpr2}
+@end example
+
+The following example demonstrates the basic functionality, putting
+parts on a single staff as polyphony and setting stem directions
+accordingly. The same variables are used for the independent parts and
+the combined staff.
+
+@lilypond[quote,verbatim]
+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 |
+ d4 c b a |
+ g4 f( e) d |
+ e1 |
+}
+
+<<
+ \new Staff \instrumentOne
+ \new Staff \instrumentTwo
+ \new Staff \partcombine \instrumentOne \instrumentTwo
+>>
+@end lilypond
+
+Both parts have identical notes in the third measure, so only one
+instance of the notes is printed. Stem, slur, and tie directions are
+set automatically, depending on whether the parts are playing solo or in
+unison. When needed in polyphony situations, the first part (with
+context called @code{one}) gets @qq{up} stems, while the second (called
+@code{two}) always gets @qq{down} stems. In solo situations, the first
+and second parts get marked with @qq{Solo} and @qq{Solo II},
+respectively. The unison (@notation{a due}) parts are marked with the
+text @qq{a2}.
+
+Both arguments to @code{\partcombine} will be interpreted as separate
+@code{Voice} contexts, so if the music is being specified in relative
+mode then @emph{both} parts must contain a @code{\relative} function,
+i.e.,
+
+@example
+\partcombine
+ \relative @dots{} @var{musicexpr1}
+ \relative @dots{} @var{musicexpr2}
+@end example
+
+@noindent
+A @code{\relative} section that encloses a @code{\partcombine} has no
+effect on the pitches of @code{@var{musicexpr1}} or
+@code{@var{musicexpr2}}.
+
+@funindex \partcombineChords
+@funindex partcombineChords
+@funindex \partcombineApart
+@funindex partcombineApart
+@funindex \partcombineUnisono
+@funindex partcombineUnisono
+@funindex \partcombineSoloI
+@funindex partcombineSoloI
+@funindex \partcombineSoloII
+@funindex partcombineSoloII
+@funindex \partcombineAutomatic
+@funindex partcombineAutomatic
+
+In professional scores, voices are often kept apart from each other for
+long passages of music even if some of the notes are the same in both
+voices, and could just as easily be printed as unison. Combining notes
+into a chord, or showing one voice as solo is, therefore, not ideal as
+the @code{\partcombine} function considers each note separately. In this
+case the @code{\partcombine} function can be overriden with the
+following commands:
+
+Commands ending in @code{...Once} apply only to the next note in the
+music expression.
+
+@itemize
+@item
+@code{\partcombineApart} and @code{\partcombineApartOnce} keep the
+notes as two separate voices, even if they can be combined into a chord
+or unison.
+
+@item
+@code{\partcombineChords} and @code{\partcombineChordsOnce} combine the
+notes into a chord.
+
+@item
+@code{\partcombineUnisono} and @code{\partcombineUnisonoOnce} combine
+both voices as @qq{unison}.
+
+@item
+@code{\partcombineSoloI} and @code{\partcombineSoloIOnce} print only
+voice one, and mark it as a @qq{Solo}.
+
+@item
+@code{\partcombineSoloII} or @code{\partcombineSoloIIOnce} print only
+voice two and mark it as a @qq{Solo}.
+
+@item
+@code{\partcombineAutomatic} and @code{\partcombineAutomaticOnce} end
+the functions of the commands above, and revert back to the standard
+@code{\partcombine} functionality.
+@end itemize
+
+@lilypond[quote,verbatim]
+instrumentOne = \relative c' {
+ \partcombineApart c2^"apart" e |
+ \partcombineAutomatic e2^"auto" e |
+ \partcombineChords e'2^"chord" e |
+ \partcombineAutomatic c2^"auto" c |
+ \partcombineApart c2^"apart" \partcombineChordsOnce e^"chord once" |
+ c2 c |
+}
+instrumentTwo = \relative c' {
+ c2 c |
+ e2 e |
+ a,2 c |
+ c2 c' |
+ c2 c |
+ c2 c |
+}
+
+<<
+ \new Staff { \instrumentOne }
+ \new Staff { \instrumentTwo }
+ \new Staff { \partcombine \instrumentOne \instrumentTwo }
+>>
+@end lilypond
+
+
+@snippets
+
+@lilypondfile[verbatim,lilyquote,texidoc,doctitle]
+{combining-two-parts-on-the-same-staff.ly}
+
+@lilypondfile[verbatim,lilyquote,texidoc,doctitle]
+{changing-partcombine-texts.ly}
+
+
+@seealso
+Music Glossary:
+@rglos{a due},
+@rglos{part}.
+
+Notation Reference:
+@ref{Writing parts}.
+
+Snippets:
+@rlsr{Simultaneous notes}.
+
+Internals Reference:
+@rinternals{PartCombineMusic},
+@rinternals{Voice}.
+
+@knownissues
+
+All @code{\partcombine...} functions can only accept two voices and are
+not designed to work with lyrics; such that when one of the voices is
+explicitly named in order to attach lyrics to it, the partcombiner will
+stop working.
+
+@code{\partcombine...} functions cannot be placed inside a @code{\times}
+or @code{\relative} block.
+
+If @code{printPartCombineTexts} is set and the two voices play the same
+notes @qq{on and off}, in the same measure, the part combiner may
+typeset @code{a2} more than once in that measure.
+
+@code{\partcombine} only knows when a note starts in a @code{Voice}; it
+cannot, for example, remember if a note in one @code{Voice} has already
+started when combining notes that have just started in the other
+@code{Voice}. This can lead to a number of unexpected issues including
+@qq{Solo} or @qq{Unison} marks being printed incorrectly.
+
+@code{\partcombine} keeps all spanners (slurs, ties, hairpins etc.) in
+the same @code{Voice} so that if any such spanners start or end in a
+different @code{Voice}, they may not be printed properly or at all.
+
+If the @code{\partcombine} function cannot combine both music
+expressions (i.e. when both voices have different durations), it will
+give the voices, internally, its own custom names: @code{one} and
+@code{two} respectively. This means if there is any @qq{switch} to a
+differently named @code{Voice} context, the events in that differently
+named @code{Voice} will be ignored.
+
+Refer also to @emph{Known issues and warnings} when using
+@code{\partcombine} with tablature in @ref{Default tablatures} and the
+@emph{Note} in @ref{Automatic beams} when using automatic beaming.
+
+
+@node Writing music in parallel
+@unnumberedsubsubsec Writing music in parallel
+
+@cindex writing music in parallel
+@cindex interleaved music
+@cindex parallel music
+@funindex \parallelMusic
+@funindex parallelMusic
+
+Music for multiple parts can be interleaved in input code. The
+function @code{\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.
+
+@warning{Bar checks @code{|} must be used, and the measures must
+be of the same length.}
+
+@lilypond[quote,verbatim]
+\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 }
+>>
+@end lilypond
+
+Relative mode may be used. Note that the @code{\relative} command
+is not used inside @code{\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
+@code{voiceA} ignore the notes in @code{voiceB}.
+
+@lilypond[quote,verbatim]
+\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 }
+>>
+@end lilypond
+
+This works quite well for piano music. This example maps four
+consecutive measures to four variables:
+
+@lilypond[quote,verbatim]
+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
+ >>
+ }
+ >>
+}
+@end lilypond
+
+
+@seealso
+Learning Manual:
+@rlearning{Organizing pieces with variables}.
+
+Snippets:
+@rlsr{Simultaneous notes}.
projects / lilypond.git / blobdiff