Ciaran Carson.

It's a factual book, written as a Kerouac-like road trip. I thought it was rather overdone and hypey.

Nobody's yet mentioned Lovecraft's "The Music of Erich Zann" - only a short story but rather good. I don't know if Lovecraft ever used music as a topic elsewhere.

There is a three-volume fictionalized biography of Beethoven by John Suchet. Somehow I expect it to be an unrewarding slog, but others may think differently.

Given the success of "Pride and Prejudice and Zombies", there has to be an opportunity for a similar mashup. I once suggested Dave Bulmer as Yog-Sothoth the Eater of Souls; Paganini as Dracula is a natural. And perhaps a combo of Keith Richards and Dorian Gray.