If you've never seen Urinetown, its Tony Awards performance is a good introduction and, below the fold, one of my favorite parts of the book, which because it's not in the soundtrack is a fragment I had forgotten:
LITTLE SALLY: Say, Officer Lockstock, I was thinkin'. We don't spend much time on hydraulics, do we?
LOCKSTOCK: Hydraulics, Little Sally?
LITTLE SALLY: You know, hydraulics. Hydration. Irrigation. Or just plain old laundry. Seems to me that with all the talk of water shortage and drought and whatnot, we might spend some time on those things, too. After all, a dry spell would affect hydraulics, too, you know.
LOCKSTOCK: Why, sure it would, Little Sally. But ... How shall I put it? Sometimes--in a musical--it's better to focus on one big thing rather than a lot of little things. The audience tends to be much happier that way. And it's easier to write.
(LITTLE SALLY thinks this over.)
LITTLE SALLY: One big thing, huh?
LOCKSTOCK: That's right, Little Sally.
LITTLE SALLY: Oh. (Pause.) Then why not hydraulics?
LOCKSTOCK: (Chuckles.) Run along, then, Little Sally. Wouldn't want you to miss last call. Ms. Pennywise won't hold the gate forever, you know.