on our last show, the picnic, it was set in the 20s so we used 20s jazz type stuff during set changes, last year our show was a series of one scene sketches written by students, so after each sketch i played a song that pertained to that sketch, like after one dealing with the devil i played "devil went down to georgia" or one about a writer i played "paperback writer" there is no specific music, you have to do it based on the show, unless u wanna get some crappy elevator music evereone hates, but i wouldnt suggest it.