Crying by Roy Orbison can make for an amazing ballad. Another one is Don't You Know by Della Reese which is actually a contemporary take on Musetta's Waltz from La Boheme. Gorgeous song. You don't want to go
too 50s because you have to remember Buddy Holly was really ahead of his time and he didn't quite fit into a standard genre. Late 50s/early 60s rock and roll will work. From what I remember, the show really doesn't feature any female soloists vocally, so you don't have to be too picky. Show off your voice and have fun with it and you should be fine.
"What can you expect from a bunch of seitan worshippers?" - Reginald Tresilian