I LOVE THIS THREAD!
Okay, I have some... the first one might be a little bit of a push but let's see where it goes:
1.) Set in Steeltown USA, this rock musical, composed by Mark Blitzstein, explores the torment of a Danish Prince planning revenge on his uncle. The flop closed in 1976 and was forbidden by Actor's Equity to be performed on a stage ever again.
2.) This 1930s Rodgers and Hart Musical chronicles the lives of three newly expectant couples and featured the soon to be pop standards "My Funny Valentine," "The Lady is a Tramp," and "Johnny One Note".
Going to a musical late in its run is like going to a prostitute late in her shift.