Re: Acciaccaturas and slashed stems

[David Kastrup]

Peter Bjuhr <address@hidden> writes:

> With the support of Janek and Franciszek I now got the compilation to
> work. I should add that the problem was not in the script but due to
> misuse from my part!

If you cut your hand with a knife by letting the handle slip, it's a
misuse of the knife.  Still some knifes come with guards.

"Misuse" is still worth investigating.

> Attached is a test file I just run. If you David and Gilberto (or
> anyone else of course) have any more test ideas for this I'll be happy
> to take part!

> % this could be the notation of previous ex. w. split beaming in my opinion
> { 
>   \new Voice {
>   \grace { c'16 d' e' f' e' f' g' \fermata } \grace { a'8 g' a'  } g'4 
>   }
> }
> % 27:55: warning: adding note head to incompatible stem (type = 1/16)
> %   \grace { c'16 d' e' f' e' f' g' \fermata } \grace { 
> %                                                       a'8 g' a'  } g'4 
> % 27:55: warning: maybe input should specify polyphonic voices
> %   \grace { c'16 d' e' f' e' f' g' \fermata } \grace { 
> %                                                       a'8 g' a'  } g'4 

Well, that's not a problem of Grace_auto_beam_engraver.  LilyPond in
general is not happy with multiple grace groups in succession.  However,
it _is_ quite appalling just _how_ unhappy it is with this one:

The right way to break up the beaming is using explicit beaming:
{ \grace { c'16 d' e' f' e' f' g' \fermata a'8[ g' a'] } g'4 }

or similar:
{ \grace { c'16 d' e' f' e' f' g' \fermata a'8\noBeam g' a' } g'4 }

The decisive thing is that LilyPond will only start an automatic beam at
the start of the grace group.  You might need a \noBeam there, or at the
first note that should escape the autobeaming.

-- 
David Kastrup