I'm writing a piece in Lilypond in verse/refrain form, in which the verses are only a singer ("Cantor") and a cello, and the refrain has SATB parts as well. I'm trying to use an explicit line break to cleanly end the SATB staffs at the end of the refrain. However, when I do, this is what I get:
when, of course, what I'd like from Lilypond is
I've seen this from Lilypond before, but it seems to happen with no great consistency, and remarkably never seems to affect the end of anything I write (it doesn't only happen if a staff ends in the middle of the piece, but always seems to go away before I'm finished), but I can't get this instance to go away.
So, StackExchange, what do I do? Bonus points if your solution allows me to put the linebreak at the 2/3 point in the bar so the pickup to the next measure is on the next line (I know how to do that by itself, but not without the staffs being messed up). Also, please focus your comments on the Lilypond issue and not the music on the page. I know it's not great.