@c \version "2.11.61"
-@ignore
-GDP TODO list
-
-1.2.3.4 Polymetric notation
-Quite extensive changes. Could you please check through. Divided
-into three
-sections. Necessarily uses tweaks.
-@end ignore
-
@node Rhythms
@section Rhythms
@node Polymetric notation
@unnumberedsubsubsec Polymetric notation
+@c This section necessarily uses \set
+@c This is acceptable -td
+
@cindex double time signatures
@cindex signatures, polymetric
@cindex polymetric signatures
@cindex meter, polymetric
-Polymetric notation is supported, either explicitly or through
-clever use of markup features.
+Polymetric notation is supported, either explicitly or by modifying
+the visible time signature symbol and scaling the note durations.
-@strong{Staves with different time signatures, equal measure lengths}
+@strong{@i{Staves with different time signatures, equal measure lengths}}
This notation can be created by setting a common time signature
for each staff but replacing the symbol manually by setting
@code{timeSignatureFraction} to the desired fraction and scaling
the printed durations in each staff to the common time
-signature. This is done with @code{\scaleDurations}, which
-is used in a similar way to @code{\times}, but does not create
-a tuplet bracket, see @ref{Scaling durations}.
+signature; see @ref{Time signature}. The scaling is done with
+@code{\scaleDurations}, which is used in a similar way to
+@code{\times}, but does not create a tuplet bracket; see
+@ref{Scaling durations}.
In this example, music with the time signatures of 3/4, 9/8, and
10/8 are used in parallel. In the second staff, shown durations
are multiplied by 2/3, as 2/3 * 9/8 = 3/4, and in the third
staff, shown durations are multiplied by 3/5, as 3/5 * 10/8 = 3/4.
+It will often be necessary to insert beams manually, as the
+duration scaling affects the autobeaming rules.
@lilypond[quote,verbatim,fragment]
-\relative c' { <<
+\relative c' <<
\new Staff {
\time 3/4
c4 c c |
\time 3/4
\set Staff.timeSignatureFraction = #'(9 . 8)
\scaleDurations #'(2 . 3)
- \repeat unfold 6 { c8[ c c] }
+ \repeat unfold 6 { c8[ c c] }
}
\new Staff {
\time 3/4
\scaleDurations #'(3 . 5) {
\repeat unfold 2 { c8[ c c] }
\repeat unfold 2 { c8[ c] } |
- c4. c4. \times 2/3 { c8 c c } c4
+ c4. c4. \times 2/3 { c8[ c c] } c4
}
}
->> }
+>>
@end lilypond
-@strong{Staves with different time signatures, unequal bar lengths}
+@strong{@i{Staves with different time signatures, unequal bar lengths}}
Each staff can be given its own independent time signature by
-moving the @code{Timing_translator} to the @code{Staff} context.
+moving the @code{Timing_translator} and the
+@code{Default_bar_line_engraver} to the @code{Staff} context.
@lilypond[quote,verbatim]
\layout {
@rglos{polymetric time signature},
@rglos{meter}.
-Notation Reference: @ref{Scaling durations}
+Notation Reference:
+@ref{Time signature,
+@ref{Scaling durations}.
Snippets:
@rlsr{Rhythms}.
Internals Reference:
@rinternals{TimeSignature},
@rinternals{Timing_translator},
+@rinternals{Default_bar_line_engraver},
@rinternals{Staff}.
@knownissues