Without looking it up, Frank never played an instrument to the best of my knowledge, but I DID hear that he wrote That Christmas song he did .... "Oh by gosh by golly" ... or is it called "Mistletoe & Holly" Hmmmm....
I've heard rumors that he had perfect pitch but never saw anything to document it. One thing he did better than anybody ....
Surround himself with the best in players and arrangements. It'd be tough for anyone to fail in front of the bands that backed him up.