Issue 1525 in lilypond: Autobeaming can require zero-length beat

[lilypond]

Status: Accepted
Owner: ----
Labels: Type-Defect Priority-Critical

New issue 1525 by address@hidden: Autobeaming can require  
zero-length beat
http://code.google.com/p/lilypond/issues/detail?id=1525

Note that this may be related to issue 1524.

Report by Phil:
I'm no expert on this, but have just given the docs a good read, and the  
Notation Ref says:

"By default baseMoment is set to one over the denominator of the time  
signature" - so in this case, it's a quarter note.  You're trying to set  
beams on eighth note boundaries, so it won't work.  You also need to add  
\set Timing.beamExceptions = #'() to stop beamExcpetions taking over.  That  
said, I still think there may be a bug here, and would welcome a comment  
from a beamMeister.  The following gives the attached image:

\relative c' {
    \time 3/4
    c8 c c c c c
    \set Timing.baseMoment = #(ly:make-moment 1 8)
    \set Timing.beamExceptions = #'()
    \set Timing.beatStructure = #'(3 3)
    c c c c c c
    \set Timing.beatStructure = #'(0 3 3)
    c c c c c c
}

Carl:
This is also a bug.  One should never need to make a zero-length beat to
affect autobeaming behavior.  I don't know if it's the same bug or another
bug.

Phil's code is exactly what I would have written as the way to solve the
original request (except that I would have reversed the order of the
beamExceptions and beatStructure settings.  I don't know why it didn't work.
Again, it may be an issue of the special rule for beaming 3/4 time.

If nobody else does it in the meantime, I'll investigate when I get the
time.



Attachments:
        BeamExceptions.png  3.3 KB