Well I've now read it and quite enjoyed it. Book is divided into 4 parts each built around a jazz musician: Jo Jones, Fats Waller, Pops and Duke. He tells other, probably apocryphal, stories about gigs he implies he attended: he may have seen Trane with Monk but I doubt if he was present at an encounter between Buddy Rich and Big Sid Catlett. (Big Sid died when Appel was 15).
I don't buy many of his interpretations of works of art (for him a cigar is never just a cigar) but his close reading jazz recordings is really interesting and his writing on Joyce's Ulysses is terrific.