Guide, node Updating translation committishes..
@end ignore
-@c \version "2.15.39"
+@c \version "2.16.0"
@node Rhythms
@section Rhythms
@funindex \set
@funindex set
+When automatic beaming is enabled, the placement of automatic beams
+is determined by three context properties:
+@code{baseMoment}, @code{beatStructure}, and @code{beamExceptions}.
+If a @code{beamExceptions} rule is defined for the time signature in
+force, that rule is used to determine the beam placement. If no
+@code{beamExceptions} rule is defined for the time signature in force,
+the beam placement is determined by the settings of @code{baseMoment}
+and @code{beatStructure}.
+
+By default, @code{beamExceptions} rules are defined for most common
+time signatures, so the @code{beamException} rules must be disabled
+if automatic beaming is to be based on @code{baseMoment} and
+@code{beatStructure}. The @code{beamExceptions} rules are disabled
+by
+
+@example
+\set Timing.beamExceptions = #'()
+@end example
+
+
+@subsubheading @i{Beaming based on @code{baseMoment} and @code{beatStructure}}
+
In most instances, automatic beams will end at the end of a beat.
The ending points for beats are determined by the context properties
@code{baseMoment} and @code{beatStructure}. @code{beatStructure}
is a scheme list that defines the length of each beat in the measure
in units of @code{baseMoment}. By default, @code{baseMoment} is
-the one over numerator of the time signature. By default,
+one over the denominator of the time signature. By default,
each unit of length @code{baseMoment} is a single beat.
@lilypond[quote,relative=2,verbatim]
c16^"(3+2)" c c c c |
@end lilypond
+If a common time signature is being used, @code{beamExceptions}
+@emph{must} be disabled to enable @code{beatStructure} to work.
+The @code{\set Timing.beamExceptions = #'()} command can always
+be included if beaming is being determined by @code{beatStructure}.
+
+@lilypond[quote,relative=2,verbatim]
+\time 4/4
+a8^"default" a a a a a a a
+
+\set Timing.baseMoment = #(ly:make-moment 1 4)
+\set Timing.beatStructure = #'(1 1 1 1)
+a8^"no change" a a a a a a a
+
+\set Timing.beamExceptions = #'()
+\set Timing.baseMoment = #(ly:make-moment 1 4)
+\set Timing.beatStructure = #'(1 1 1 1)
+a8^"changed" a a a a a a a
+@end lilypond
+
Beam setting changes can be limited to specific contexts. If no
setting is included in a lower-level context, the setting of the
enclosing context will apply.
the time signature. Any exceptions to this default can be found in
@file{scm/time-signature-settings.scm}.
+@subsubheading @i{Beaming based on @code{beamExceptions}}
+
Special autobeaming rules (other than ending a beam on a beat)
are defined in the @code{beamExceptions} property.
\repeat unfold 8 {c8}
@end lilypond
-In traditional engraving, eighth notes can have special beaming rules.
-A measure consisting of only eighth notes can be beamed in one. This rule is
-controlled by the context property @code{beamWholeMeasure}:
+In a similar fashion, eighth notes in 3/4 time are beamed as a full
+measure by default. To beam eighth notes in 3/4 time on the beat,
+reset @code{beamExceptions}.
@lilypond[quote,verbatim,relative=2]
\time 3/4
-% By default we beam in one
-\repeat unfold 6 { a8 }
-% We can avoid beaming in one
-\set Timing.beamWholeMeasure = ##f
-\repeat unfold 6 { a8 }
+% by default we beam in (6) due to beamExceptions
+\repeat unfold 6 {a8} |
+% This will beam (1 1 1) due to beatLength
+\set Timing.beamExceptions = #'()
+\repeat unfold 6 {a8}
@end lilypond
-In some engraving from the Romantic and Classical periods,
-a half-measure of eighth notes can be beamed
-together even though this violates the general rule (see Gould, p. 153).
-This behavior is controlled by the context property @code{beamHalfMeasure}:
+In engraving from the Romantic and Classical periods,
+beams often begin midway through the measure in 3/4 time,
+but modern practice is to avoid the false impression of 6/8 time
+(see Gould, p. 153). Similar situations arise in 3/8 time.
+This behavior is controlled by the context property @code{beamHalfMeasure},
+which has effect only in time signatures with 3 in the numerator:
@lilypond[quote,verbatim,relative=2]
\time 3/4
-% By default we avoid half-measure beams
r4. a8 a a |
-% We can allow half-measure beams
-\set Timing.beamHalfMeasure = ##t
+\set Timing.beamHalfMeasure = ##f
r4. a8 a a |
@end lilypond
-@i{@strong{How automatic beaming works}}
+@subsubheading @i{How automatic beaming works}
When automatic beaming is enabled, the placement of automatic beams
is determined by the context properties
c1
@end lilypond
+Additionally there is an @code{\inStaffSegno} command which
+creates a segno bar, placed in cooperation
+with the @code{\repeat volta} command.
+
In scores with many staves, a @code{\bar} command in one staff is
automatically applied to all staves. The resulting bar lines are
\MyCadenza c'1
}
\new Staff {
- $(mmrest-of-length MyCadenza)
+ #(mmrest-of-length MyCadenza)
c'1
- $(skip-of-length MyCadenza)
+ #(skip-of-length MyCadenza)
c'1
}
>>
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