@end itemize
+
@node Chord repetition
@unnumberedsubsubsec Chord repetition
+@cindex Chord, repetition
+@cindex repetition, using @code{q}
+
In order to save typing, a shortcut can be used to repeat the preceding
chord. The chord repetition symbol is @code{q}:
other non-chorded notes or rests have been added since.
@lilypond[verbatim,quote,relative=2]
-<a c e>1 c4 q2 r8 q8
+<a c e>1 c'4 q2 r8 q8 |
+q2 c, |
@end lilypond
However, the chord repetition symbol does not retain any dynamics,
-articulation or ornamentation within, or attached to the previous chord.
+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
+<a-. c\prall e>1\sfz c'4 q2 r8 q8 |
+q2 c, |
+@end lilypond
+
+To have some of them retained, the @code{\chordRepeats} function can be
+be called explicitly with an extra argument specifying a list of
+@var{event types} to keep unless events of that type are already
+present on the @code{q} chord itself.
+
+@lilypond[verbatim,quote]
+\relative c'' {
+ \chordRepeats #'(articulation-event)
+ { <a-. c\prall e>1\sfz c'4 q2 r8 q8-. } |
+ q2 c, |
+}
@end lilypond
+Here using @code{\chordRepeats} inside of a @code{\relative} construction
+produces unexpected results: once chord events have been expanded, they
+are indistinguishable from having been entered as regular chords, making
+@code{\relative} assign an octave based on their current context.
+
+Since nested instances of @code{\relative} don't affect one another,
+another @code{\relative} inside of @code{\chordRepeats} can be used for
+establishing the octave relations before expanding the repeat chords.
+In that case, the whole content of the inner @code{\relative} does not
+affect the outer one; hence the different octave entry of the final note
+in this example.
+
+@c Without \new Voice, implicit voice creation does the dumbest thing.
+@lilypond[verbatim,quote]
+\new Voice
+\relative c'' {
+ \chordRepeats #'(articulation-event)
+ \relative c''
+ { <a-. c\prall e>1\sfz c'4 q2 r8 q8-. } |
+ q2 c |
+}
+@end lilypond
+
+Interactions with @code{\relative} occur only with explicit calls of
+@code{\chordRepeats}: the implicit expansion at the start of typesetting
+is done at a time where all instances of @code{\relative} have already
+been processed.
+
@seealso
Notation Reference:
@ref{Chord notation},
Here different rhythms cause no problems.
+@cindex collisions, clashing note columns
+@cindex collisions, ignoring
+
+@knownissues
+If notes from two or more voices, with stems in the same direction, are
+placed at the same position on the staff and have no shift (or have the
+same shift specified), the message:
+
+@example
+warning: ignoring too many clashing note columns
+@end example
+
+will appear during compilation. This message can be suppressed by:
+
+@example
+\override NoteColumn #'ignore-collision = ##t
+@end example
+
+However, this not only suppresses the warning but will prevent any
+collision resolution whatsover and may have other unintended effects
+(also see @emph{Known Issues} in @ref{Collision resolution}).
+
@node Clusters
@unnumberedsubsubsec Clusters
even simultaneously. In such a case no attempt is made to
automatically avoid collisions between ordinary notes and clusters.
-
@seealso
Music Glossary:
@rglos{cluster}.
@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 produce MIDI output.
+
@node Multiple voices
@subsection Multiple voices
>>
@end lilypond
+@warning{Lyrics, spanners (such as slurs, ties, hairpins etc.) cannot be
+created @q{across} voices.}
+
@strong{@i{Identical rhythms}}
In the special case that we want to typeset parallel pieces of music
@code{\oneVoice}.
@endpredefined
-
@seealso
Learning Manual:
@rlearning{Voices contain music},
@code{\voiceNeutralStyle}.
@endpredefined
-
@seealso
Learning Manual:
@rlearning{I'm hearing Voices},
>>
@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
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{\shiftOff}.
@endpredefined
-
@snippets
-
@lilypondfile[verbatim,quote,texidoc,doctitle]
{additional-voices-to-avoid-collisions.ly}
@lilypondfile[verbatim,quote,texidoc,doctitle]
{forcing-horizontal-shift-of-notes.ly}
-
@seealso
Music Glossary:
@rglos{polyphony}.
@rinternals{NoteCollision},
@rinternals{RestCollision}.
+@cindex collisions, ignoring
+
+@knownissues
+Using @code{\override NoteColumn #'ignore-collision = ##t} will cause
+differently headed notes in different voices to merge incorrectly.
+
+@lilypond[quote,relative=1,verbatim]
+\mergeDifferentlyHeadedOn
+<< { c16 a' b a } \\ { c,2 } >>
+\override NoteColumn #'ignore-collision = ##t
+<< { c16 a' b a } \\ { c,2 } >>
+@end lilypond
@ignore
@knownissues
are at the same time differently dotted are not clear.
@end ignore
+
@node Automatic part combining
@unnumberedsubsubsec Automatic part combining
@lilypondfile[verbatim,quote,texidoc,doctitle]
{changing-partcombine-texts.ly}
-
@seealso
Music Glossary:
@rglos{a due},
@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
}
@end lilypond
-
@seealso
Learning Manual:
@rlearning{Organizing pieces with variables}.