Documentation/snippets/new/conducting-signs,-measure-grouping-signs.ly

   1 \version "2.13.29"
   2
   3 \header {
   4   lsrtags = "rhythms"
   5   texidoc = "
   6 Beat grouping within a measure is controlled by the context property
   7 @code{beatStructure}.  Values of @code{beatStructure} are
   8 established for many time signatures in
   9 @file{scm/time-signature-settings.scm}.  Values of @code{beatStructure}
  10 can be changed or set with @code{\set}.
  11 Alternatively, the
  12 Scheme function @code{set-time-signature} can be used to both
  13 set the time signature and establish the beat structure.
  14 @code{set-time-signature}, takes three arguments: the
  15 number of beats, the beat length, and the internal grouping of beats in
  16 the measure.  @code{\time} and @code{set-time-signature} both apply
  17 to the @code{Timing} context, so they will not reset values of
  18 @code{beatStructure} or @code{baseMoment} that are set in
  19 other lower-level contexts, such as @code{Voice}.
  20
  21 If the @code{Measure_grouping_engraver} is included
  22 in one of the display contexts, measure grouping signs will be
  23 created.  Such signs ease reading rhythmically complex modern music.
  24 In the example, the 9/8 measure is grouped in two different
  25 patterns using the two different methods, while the 5/8 measure
  26 is grouped according to the default setting in
  27 @file{scm/time-signature-settings.scm}:
  28 "
  29   doctitle = "Conducting signs, measure grouping signs"
  30 }
  31
  32
  33 \score {
  34   \new Voice \relative c'' {
  35     \time 9/8
  36     g8 g d d g g a( bes g) |
  37     \set Timing.beatStructure = #'(2 2 2 3)
  38     g8 g d d g g a( bes g) |
  39     #(set-time-signature 9 8 '(4 5))
  40     g8 g d d g g a( bes g) |
  41     \time 5/8
  42     a4. g4 |
  43   }
  44   \layout {
  45     \context {
  46       \Staff
  47       \consists "Measure_grouping_engraver"
  48     }
  49   }
  50 }