Cross staff beams

[Alberto Simões]

Hello,

I managed to get a cross-staff beam, kneed beam, I think, with this 
code, and with the appearence in attach:

d8[ cis a \change Staff = "lower" \stemUp g] |
  fis4 \change Staff = "upper"

To reduce stem collision I forced the stemUp there, and the voice in the 
lower beam has a stemDown.

Although acceptable, the effect is not beautiful.

Is there any way to tweak it a little?

Thanks,
ambs

crossstaff.gif
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