Temporary div. multiple staffs

[Evan Driscoll]

Another question, one I've struggled with before.

The part splits out temporarily into divisi parts on multiple staffs. I always have trouble getting the correct incantations to get the correct result.

A naive attempt results in http://lilybin.com/1l8whf/5. This is enough to keep working, but it looks bad -- barlines don't cross between staffs, and there's no grouping a la https://lilypond.org/doc/v2.22/Documentation/69/lily-9c91c2b7.png from the manual.

I can get a pair of staffs that are correct on their own by creating a StaffGroup with two new staffs -- http://lilybin.com/1l8whf/9 -- but the original staff continues through. Omitting the explicit \new Staff invocations doesn't help -- http://lilybin.com/1l8whf/11.

What's the right way to do this?

Evan