How to put vertical space into a page?

[Alan McConnell]

Assembled Wisdom!

I have a simple .ly file, of a four-bar change to a
Schubert string trio.  It is one line of staff.

Below it, I wish to put the violin part(one line),
then the viola part, then the cello part.  Object:
so people can download, print out, and then cut
the individual parts out to paste into their own
music.

So I want

   Trio score

        (vertical space)

   Violin part

        (vertical space)

   Viola part

        (vertical space)

   Cello part

The Trio score, and the three parts, are all fine, ready to
go.   But how to put in the (vertical space)s?

I read about \layout  and about \paper, and I've done some
experimenting, but without success.

I am running  lilypond v 2.14.2, on my Debian squeeze box.

TIA for anticipated help!

Alan

-- 
Alan McConnell :  http://patriot.net/users/alan
    Music is still the most important aspect
    of good living. (Al Abrams)