hearthemsing22 said: ""A Musical" from Something Rotten!"
I second Class, A Musical, A Little Priest.
I would also add Bosom Buddies and Gooch's Song from Mame, The Grass is Always Greener from Woman of the Year (maybe the only good thing about that show), Cellblock Tango from Chicago, The King of Old Broadway, Betrayed, Keep it Gay, Heil Myself, Haben Zie, and still others from The Producers, You Gotta Have a Gimmick from Gypsy, Everybody Oughta Have a Maid from A Funny Thing, I Don't Understand the Poor from A Gentleman's Guide, I'll Never Be Jealous Again from The Pajama Game.