Cluster chord glissando across staves

[David Bellows]

Hello everyone,

I'm working on a piece for piano that uses a kind of cluster chord glissando that goes from the bass clef to the treble clef. When I originally engraved the piece by hand, I just drew a cluster chord in the bass and added lines connecting it to a cluster chord in the treble (the whole effect taking up an entire measure).  But I'm having troubles indicating this in Lilypond.

I thought using an actual cluster chord would look the best so I came up with this bit of code (along with some hidden rest notes):

\time 6/8

\makeClusters { <a,, e,>2 \change Staff = "upper" <g'' d'''>8 }

It works OK. The problem is that the cluster chord in the treble clef, the end of the cluster, comes up pretty far short of the bar line. In fact it looks like it gets just past the halfway mark.  I've fiddled with the numbers a good bit but this is the best I've been able to come up with.

I then tried adding more chords inside the cluster:

\makeClusters { <a,, e,>4  <g d'> \change Staff = "upper"  <a' e''>8 <g'' d'''> }

This pushes it over even more without quite making it far enough over (though if this is the closest I can get I can live with it).

I then tried using \markup and \filled-box,  \glissando,  \draw-line, and \beam with lots of hidden notes and multiple voices but have been unable to get anything close to the result I want.  I'm sure with enough fiddling and getting Lilypond to ignore collisions I could make it work but since I'm going to be using this technique throughout this piece with differing parameters I was hoping to do something that would require a lot less fiddling around and modifications.

So, does anyone have any ideas about using the methods I've talked about here or some other approach to notating this technique?

Thanks,

Dave