Re: recent beaming change?

[Trevor Daniels]

Patrick McCarty wrote Re: recent beaming change?


> > On Sat, Apr 25, 2009 at 8:31 AM, Andrew Hawryluk 
> > <address@hidden> wrote:
> > > My latest LilyPond build (2.13.1, 24 Apr 2009) produces 
> > > different
> > > beaming than my last build.
> > >
> > > e.g. {c''8 c'' c'' c''}
> > > used to produce |_|_|_|
> > > and now it gives me |_| |_|
> > >
> > > Was this intentional?
> >
> > Yes, this was changed recently. The reasons are listed here:
> >
> > http://lists.gnu.org/archive/html/bug-lilypond/2009-03/msg00126.html
> >
> > I don't know if the plans to revise the auto-beaming code (being
> > discussed by Carl, Trevor, and Neil) will address this issue.
> > Clearly, it would be better to allow for this "special case", 
> > since
> >
> > |_|_|_|
> >
> > is much more common than
> >
> > |_| |_|
>
> Oops.  I should elaborate a little more about this.
>
> The first beaming pattern used to be the default in certain cases
> (e.g. 4/4 time on beats 1 and 3), and this beaming pattern can 
> still
> be used by modifying beatLength, as Trevor described.
>
> But it is reasonable to expect users to use "\set beatLength =
> #(ly:make-moment 1 2)" if they want the first beaming pattern, 
> which
> is more common?

I can only repeat what I said in the thread referenced above, namely
that the new default permits the correct beaming of

\relative c'' {
a16 a a8 a a
a8 a16 a a8 a
a8 a a16 a a8
a8 a a a16 a  % beaming is different
}

Also, it seems easier to set beatLength to go from 2 to 4 beamed
quavers than to revert auto-beaming rules if you wanted 2 rather
than 4 beamed quavers.  Lily can't do both by default, and I think
the new behaviour makes the better compromise.  I tried to reduce
the number of auto-beaming rules to minimise the need to revert
them.  But I'm quite happy to change the beaming rules back if a
majority of users prefer the old default.

That said, Carl is still hoping to unify the behaviour which would
make overrides to the beaming behaviour far more rational.

Trevor