percussion stuff

[David Bobroff]

> Mostly, I deal with marching percussion, but the same sort of stuff
> applies
> to all percussion really.  The main thing is the slashes through the
> notes,
> and the grace notes without slurs.

Grace notes using \grace do not by default use slurs.  You can also set
the single grace notes to have a slash through them.  This was posted
recently to get that effect:

\grace{\once \property Voice.Stem \override #'stroke-style = #"grace"
your grace note here}

Using \grace will not make a slur.  Using \acciaccatura and \appogiatura
will.

-David