Rhythm improvements

• By default, strictly alternating meters consisting of 4/4 and 2/2 are printed in a historic style using multiple C or cut-C symbols.

  {
    \time #'((2 . 2) (2 . 2))
    b'1 2 2
  }
  

  

• The automatic beaming algorithm now can be told to interrupt an automatically created beam at some point using \beamBreak. Similarly, using \noBeamBreak, two adjoining notes can be forced to get beamed together:

  \relative {
    c''8 c c c d d \beamBreak d d
    \time 2/4
    c8 8 8 8
    8 8 \noBeamBreak 8 8
    4. 8 \noBeamBreak
    8 4 8
  }