Re: Looking for proper beam grouping

[Trevor Daniels]

Anthony W. Youngman Saturday, March 28, 2009 3:50 PM
> In message <address@hidden>, Trevor
> Daniels <address@hidden> writes
> > Carl, you wrote Tuesday, February 24, 2009 1:43 AM
> >
> > > On 2/23/09 12:52 PM, "Maarten Deen" <address@hidden> wrote:
> > >
> > > > I have a piece of music in 3/4 which has bars like { d4. c8 b8. 
> > > > a16 }
> > > > Lilypond groups the last three notes together, making it look 
> > > > like a
> > > > 6/8
> > > > measure, but I want the c8 to be separate and only the b8. a16 
> > > > to  be
> > > > grouped
> > > > (like a proper 3/4 would look like).
> > > >
> > > > I've tried some settings, like #(override-auto-beam-setting 
> > > > '(end  * * * *)
> > > > 1
> > > > 4)
> > > > or \set beatGrouping = #'(4 4 4) but to no avail.
> > >
> > > The proper way to set beatGrouping is #'(1 1 1), which means 
> > > group  1
> > > beat, 1
> > > beat 1 beat, where a beat is defined by the time signature as a 
> > > 1/4
> > > note.
> > >
> > > But this doesn't work properly, and it should.
> > >
> > > I think this is a bug in the autobeaming code.  Could you please 
> > > send
> > > a bug
> > > report to bug-lilypond?
> >
> > This is not a bug.  There is still a general auto-beam
> > setting for 3/4 time which inhibits beatGrouping.
> >
> > beatBrouping should work with the override
> >
> > #(revert-auto-beam-setting '(end * * 3 4) 3 4)
> >
> >
> > I was waiting for 2.13 before I completed this work, as
> > changing the default beaming did not seem right during
> > a stable release.
> Just tried to do this (2.12.2) and I'm getting 6/8 beaming in a 
> 3/4
> passage :-( Am I doing anything stupid?
>
> voiceTimeSig = {
>        \override Staff.TimeSignature #'style = #'()
>        \key f \major
>        \time 3/4
> #(revert-auto-beam-setting '(end * * 3 4) 3 4)
> \set beatGrouping = #'(1 1 1)
>        s2.*8  % mark 1
>        s2.*6  % mark 2
>        \time 2/4 s2 \time 4/4 s1

Not really stupid, as the same error catches everyone
quite often.  It's that Context thing again.  From the
way you are doing it I guess you are not placing the
revert command in every Voice.  But in this form it
applies only to the Voice context in which it appears.
To make the revert apply to every voice in a Staff you
need to add 'Staff, and to make it apply to every
Voice in every Staff you need to add 'Score, like this:

#(revert-auto-beam-setting '(end * * 3 4) 3 4 'Score)

Also the \set beatGrouping is unnecessary - that is the
default grouping in 3/4 time.

You'll be pleased to know the revert will not be required
at all in 2.13.1 to obtain this beaming.

HTH

Trevor