Different size staves?

[Todd O'Bryan]

I just started using Lilypond and am loving it. But I have a rare use
case and am having trouble.

I'm trying to set Anglican chant--basically there are several bars of
whole and half notes on a grand staff that get matched up with text
below. That part is easy, I'll just use a markup section to handle the
text.

But there's a refrain at the top and because of the lyrics, it needs
to be fairly large. I'd like the chanting notes smaller, since they
don't have lyrics and could probably fit on a single line, but I can't
figure out how to make the second score a different size from the
first.

I've tried the layout-set-staff-size trick, but the lines don't get
any smaller. I've used \with to make the fontSize and staff-space
smaller, but even when I get the notes and staves so that they're
reduced in size, the spacing hasn't changed at all and I still have
the same number of measures across as I did at full size. (They just
look a lot more airy.)

Is there any way to do this, or should I just typeset the two scores
separately, convert them to EPS, and then paste them into a LaTeX
document or something similar?

Thanks for a great program,
Todd O'Bryan