+@node Polymetric notation
+@subsection Polymetric notation
+
+Double time signatures are not supported explicitly, but they can be
+faked. In the next example, the markup for the time signature is
+created with a markup text. This markup text is inserted in the
+@internalsref{TimeSignature} grob.
+
+@lilypond[verbatim,raggedright]
+
+% create 2/4 + 5/8
+tsMarkup =\markup {
+ \number {
+ \column < "2" "4" >
+ \musicglyph #"scripts-stopped"
+ \bracket \column < "5" "8" >
+ }
+}
+
+{
+ \override Staff.TimeSignature #'print-function = #Text_item::print
+ \override Staff.TimeSignature #'text = #tsMarkup
+ \time 3/2
+ c'2 \bar ":" c'4 c'4.
+}
+@end lilypond
+
+Each staff can also have its own time signature. This is done by
+moving the @internalsref{Timing_engraver} to @internalsref{Staff}
+context.
+
+@verbatim
+\paper{
+ \context{
+ \Score
+ \remove "Timing_engraver"
+ }
+ \context{
+ \Staff
+ \consists "Timing_engraver"
+ }
+}
+@end verbatim
+
+
+Now, each staff has its own time signature.
+@verbatim
+<<
+ \new Staff {
+ \time 3/4
+ c4 c c | c c c |
+ }
+
+ \new Staff {
+ \time 2/4
+ c4 c | c c | c c
+ }
+ \new Staff {
+ \time 3/8
+ c4. c8 c c c4. c8 c c
+ }
+>>
+@end verbatim
+
+@lilypond[raggedright]
+\paper{
+ \context{
+ \Score
+ \remove "Timing_engraver"
+ }
+ \context{
+ \Staff
+ \consists "Timing_engraver"
+ }
+}
+
+\relative c' <<
+ \new Staff {
+ \time 3/4
+ c4 c c | c c c |
+ }
+
+ \new Staff {
+ \time 2/4
+ c4 c | c c | c c
+ }
+ \new Staff {
+ \time 3/8
+ c4. c8 c c c4. c8 c c
+ }
+>>
+@end lilypond
+
+
+A different form of polymetric notation is where note lengths have
+different values across staves.
+
+This notation can be created by setting a common time signature for
+each staff but replacing it manually using
+@code{timeSignatureFraction} to the desired fraction. Then the printed
+durations in each staff are scaled to the common time signature.
+The latter is done with @code{\compressmusic}, which is similar to
+@code{\times}, but does not create a tuplet bracket.
+
+
+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, so that 2/3 * 9/8 = 3/4, and in the third staff, shown durations are
+multiplied by 3/5, so that 3/5 * 10/8 = 3/4.
+
+@lilypond[raggedright,verbatim]
+\relative c' <<
+ \new Staff {
+ \time 3/4
+ c4 c c | c c c |
+ }
+ \new Staff {
+ \time 3/4
+ \set Staff.timeSignatureFraction = #'(9 . 8)
+ \compressmusic #'(2 . 3)
+ \repeat unfold 6 { c8[ c c] }
+ }
+ \new Staff {
+ \time 3/4
+ \set Staff.timeSignatureFraction = #'(10 . 8)
+ \compressmusic #'(3 . 5)
+ { \repeat unfold 2 { c8[ c c] }
+ \repeat unfold 2 { c8[ c] }
+ | c4. c4. \times 2/3 { c8 c c } c4 }
+ }
+>>
+@end lilypond
+
+
+
+
+@refbugs
+
+When using different time signatures in parallel, the spacing is
+aligned vertically, but bar lines distort the regular spacing.
+
+
+