I got in a little over my head on this one, as I should have expected. Roger Scruton has a deep knowledge of SOME forms of music, and when he is talking about things that he knows, like Beethoven's Ninth Symphony or Wagner's Ring Cycle, he has much to say, and probably, much that is valuable. I say "probably" only because I, having no real musical training, and no real philosophical training, am not in a position to judge.
I have, however, read a bit of Adorno, and listened to a fair bit of jazz. So it was somewhat interesting, but mainly disappointing, to read Scruton's glancing treatment of Adorno's attitudes towards jazz. Scruton seems to have a high opinion of some forms of jazz -- he mentions the soulfulness of Monk's "Round Midnight," but he sort of stops there. And he seems to share at times, Adorno's dismissal of a good bit of jazz, but with reservations, because he notes that Adorno relegates a lot of popular music to the scrap heap, only to say, paradoxically, that it doesn't represent the "music of the people." Now, I am not sure I have gotten Scruton's position on Adorno down to a "T", but I don't think I'm far off.
I listen to jazz and rock more than classical, and this is really a book for classical listeners, in my opinion. As I've said, Scruton sometimes mentions artists such as Thelonious Monk, and Genesis, and some other rock groups. And he doesn't fail to mention the contributions of African rhythms and polyrhythms to the development of American musics. But he doesn't go deeply into how African rhythms work or have their effects. He doesn't talk at all about Brazilian music, which I would have liked. And generally, as I have said, his analyses of Mozart and Wagner, etc...are beyond my musical grasp. This is not his failing, of course, but mine.
As other reviewers have mentioned, the first part of the book is on "Aesthetics," -- "Sounds," "Movement," "Rhythm," and so on. But he approaches these things philosophically, as the heading, "Aesthetics" would suggest. So when he deals with "Sounds" he explains a somewhat abstract notion of the "acousmatic" as the basis of his understanding of sound, and not the physical production of sound. I apologize to the reader if I have not explained this principle, but I was more interested in other things than this chapter.
To get back to the discussion of Adorno, Scruton explores Adorno's treatment of "kitsch," fairly, I think, and also does a good job of defending tonal music from Schoenberg and Adorno's insistence on atonal musical approaches.
One of the reasons I bought the book was certainly to read Scruton's treatment of Adorno. I had read a book in which Adorno called Stravinsky "hebephrenic," which is a kind of schizophrenia in which the subject is reduced to engaging in adolescent inanities. I really wanted to know what manner of man Adorno was to do this sort of a thing, and I have a feeling I will not get closer to answering this question than I have since reading Scruton's take on Adorno. If you liked this book, and have any interest in architectural aesthetics, I would recommend Scruton's "The Aesthetics of Architecture," recently republished.