I'm going to make a wild observation here about Frank. Perhaps you have seen television shows that laud the strange skills of idiot savants. I went to school with some kids almost exactly like that, especially the math geniuses, and you learned to tolerate their other assortment of weird behaviors to try to get along with them because, say, they were good at math and could figure out small shortcut quick trucks to a solution of a formula, and they'd share with us other kids how they did it, so we could do that short cut, too.
So there's the idiot savant math genuises.
Or the ones who can play a variety of musical instruments and call out for requests from one part of the audience for a song and another part of the audience for a rhythm, and another part of the audience for an instrument (want to hear that on a banjo or a piano?) and assemble all the requests together and play any of those on a variety of different instruments.
Or the ones with perfect pitch who ride on trains and hear not just the rhythm of the train (and remember a piece of music that would fit in to that) but listen to the squeak and call out that's a "B" or another scrunch is an "A".
The ones who can fly in an airplane over a landscape never
before seen and then once again on earth, paint a circular mural in astounding
detail that recreates the entire landscape they'd just seen right from the airplane window down to a crack in
the window of a building or a bird flying.
Frank was like that to a large degree with his music, he had rapid-fire synapses and could put all sorts of things together. But for me, his was a gentler form and he usually had a sense of humor about it.