I also found out an interesting little nugget about Tommy's iconic signature. Turns out, it too goes back to Playbill!
When Tommy was performing on Broadway and was greeted by fans at the stage door with Playbills in hand, he knew that because of our coated paper, he'd have to turn the Playbill over and scribble on the back in order to get the pen to start working. After doing this many times, he realized that he should just incorporate the "scribble" into the signature to save time. And so his signature stayed...scribble and all.