Re: reduce the beam width

[Noeck]

Hi Federico,

> I mean the width of the beam. 

The beam is as wide as the notes (stems) are separated, so you want to
reduce the distance between note heads. Perhaps that seems nitpicking
but it makes clear that you want to change spacings or extents of
noteheads etc. and no beam property.

I have no better solution than you found yourself. Perhaps this is a bit
nicer as the glissando still points to the place where the a is located
on the staff:

 \once \override NoteHead.stencil = #point-stencil
 \once \override TabNoteHead.stencil = #point-stencil

With these lines, the stencil is not ##f (false) as it is by using
\omit, but there is a still a note head without a size.

Cheers,
Joram