Munk I think that's a great idea! I feel that those songs that aren't always so hyped can give a lot more to an audience. I'd rather hear something like "Prayer" from Pimpernel than "She Was There" or something like "Goin' Down" from Hair as opposed to "Aquarius"
Some other great songs from older shows- "Why Was I Born" by Jerome Kern from Sweet Adeline
"Once in a While" from the Rocky Horror Show
"I Resolve" "Grand Knowing You" or "A Trip to the Library" from She Loves Me (I'm in rehearsal for it right now so kinda have the show on the brain)
"I Only Have Eyes for You" from 42nd St. (Not a show from back in the day, but not a modern musical necessarily)
"The Bus From Amarillo" from Best Little Whorehouse in Texas.
Another show that's not particuarly old but wonderful music, "You Can Always Count on Me" or "With Every Breath I Take" from City of Angels
If you have good African-American talent think of something like "When I First Saw You" or "I Am Changing" from Dreamgirls. Also there's the amazing (and yes, signature) song from The Wiz, "Home".
Hope that gave you some small idea of possibilities. If you have other questions for stuff I did a Kern revue last year at my university and have a bunch of songs from the 20's-40's of his.
Cheers,
C.
www.christopherviolett.com