Here’s a great segment from Disney’s 1946 “Make Mine Music”: All the Cats Join in.  It’s fabulous.

The background is very minimal.  It’s drawn in place as the characters need it.  This piece is very much about how the characters convey the excitement of the music, some hot Benny Goodman jazz.  The enthusiasm of these kids is positively contagious, as they rear back and fling themselves from point A and go skidding and scrambling while overshooting point b every time.  And great non-rotoscoped dancing.  I dig it.

I can’t say enough about this animated short. It’s probably my favorite Betty film, and pretty much highlights everything that was terrific in those old rubber hose cartoons.
It doesn’t really do much of a job in telling the actual fairy tale, it’s more of just a backdrop for the films zaniness.
There is a stream of utterly hallucenogenic gags, and suddenly a little Cab Calloway feature — rotoscoped right into the film as Koko — full of hot jazz and cool dance moves.

You can watch it below:

ASIFA-Hollywood Animation Archive: Filmography: Betty Boop in Snow White