Heady stuff, you all..haha. And I thought summer was for relaxing? hahahahahah...
Okay...here's a few:
Deep in a Dream - The Long Night of Chet Baker
(though very well written, this could hardly be considered a "happy" read...)
In Black and White - The life of Sammy Davis Jr
(terrific writing and from a perspective you might not consider otherwise)
Here's a couple that, although aren't musical in nature, but are written by a musician (former Wyndham Hill guitarist - Daniel Hecht)
(Skull Session is another great read...and will scare you from the first page!)
(The Babel Effect is rather heady...as the story is about a team of geniuses. Still, this guy is a very fine writer).
Alex, I think you have enough choices for several summers...haha.