Page layout frustration

[lilypond]

I'm trying to fit a piece of music onto one page. By default, lily
formats it as 11 systems, 10 on the first page, 1 on the second. So I
told lily to fit it in 10 systems - which it nicely laid out as 9 on the
first page, 1 on the second! :-(

When I tell it to fit it in 9 systems, it finally puts it on one page,
but it's all far too squashed. What I guess is happening is that it's
putting the lily tag-line on the last page, and with both header and
tagline there's only room for 9 systems.

What's annoying though, is that even though I've set top margin to zero,
there's loads of wasted space at the top of the page ... and I guess
even if I set the lily tag-line to blank, it would still need space for
it ...

How do I free up all that wasted header space or otherwise gain room to
fit my part cleanly on one page? I'd rather not delete the tag line :-)
but is there any way of simply making that not exist, either?

I've also tried to look up the source code that actually lays out the headers 
and footers, but I've ended up in a pile of Scheme I can't make head nor tail 
of (titling.scm). If I need to drill deeper, can anybody give me any pointers 
(I want to do things like redefining headers and footers so I get a band-style 
title, when I've got multiple pages it puts the title as well as instrument on 
subsequent sheets, etc etc).

Cheers,
Wol