New voices in scheme?

[Rodolfo Zitellini]

Hi all,
I have two voice passages in music written out as chords, and since I
need separate beams (up and down), i'm in the process of converting
them manually to two separate voices:

<c e>8 <d f> <e g> <f a>

becomes

<< { e8 f g a} \\ { c8 d e f } >>

Now I was wondering, is there a way I could do this in scheme? There
is a nice snippet (http://lsr.dsi.unimi.it/LSR/Snippet?id=545) that
shows how to split chords into multiple voice, I am tying to find out
how to create directly the voice instantiating in scheme.

Any ideas?

Thanks,
Rodolfo