5 @cindex polymetric music
7 @cindex scaling durations
9 It is possible to have multiple time signatures, each one in an own staffs,
10 at the same time, and have even a proper vertical alignment of the different
11 durations. This is done, firstly, by setting a common time signature for
12 each staff but replacing it manually using @code{timeSignatureFraction} to
13 the desired fraction, and secondly, by scaling the printed durations to
14 the actual, polymetric durations.
16 In this example, music with the time signatures of 3/4, 9/8 and 10/8 are
17 used in parallel. In the second staff, shown durations are multiplied by
18 2/3, so that 2/3 * 9/8 = 3/4, and in the third staff, shown durations are
19 multiplied by 3/5, so that 3/5 * 10/8 = 3/4.
25 #(define ((scale-music-function fraction) x)
26 (ly:music-compress x (ly:make-moment (car fraction) (cdr fraction))))
32 \notes \relative c' <<
39 \set Staff.timeSignatureFraction = #'(9 . 8)
40 \apply #(scale-music-function '(2 . 3))
41 \repeat unfold 6 { c8[ c c] }
46 \set Staff.timeSignatureFraction = #'(10 . 8)
47 \apply #(scale-music-function '(3 . 5))
48 { \repeat unfold 2 { c8[ c c] }
49 \repeat unfold 2 { c8[ c] }
50 | c4. c4. \times 2/3 { c8 c c } c4 }
53 \paper { raggedright = ##t }