Multiple staffs for a div. section

[Evan Driscoll]

I am probably missing something fundamental in my LilyPond knowledge that would help with the following question, but I'm not sure what it is, and I'm having a lot more difficulty than normal figuring out what to look for in the manual.

Anyway, the piece starts off in unison, then has a div. section written on multiple staffs, then comes back together.

I can get multiple staffs with

    <<
        { ...top part.. }

        \new Staff { ...bottom part ...}
    >>

but what I really want is a staff group. The bracket on the left would be nice, but even more critical are the shared barlines.

However, I can't figure out how to get a \new StaffGroup to work. If I use it as shown in the manual (but for the top-level staff creation) with my two inside, then I get *three* staves, the first one just empty.

LilyBin exemplar with a couple of my attempts: http://lilybin.com/ul6alr/5

Thanks,

Evan