Years ago (many, many) I saw on TV a musical, (on ABC TV in Australia) all I can recall of it was main characters a male, and a young female, (she was trying to get on stage or something like that, always thought it was called Babe/Baby, but not sure of that, would appreciate any help, and sorry for being so vague.
The smiley is really appropriate, coz I am real green at postings.

I'm thinking you might be talking about "42nd Street".
A girl (Peggy Sawyer) misses an audition and then becomes friends with the director. The leading lady in the play hates Peggy and unfortunately breaks her ankle before a show and Peggy ends up taking the lead in the show.

Does that sound about right?