A composer writing about music can be interesting. For example, Paul Hindemith’s “A Composer’s World” is excellent and compelling (agree or disagree, one must deal with the propositions put forth by Hindemith), while Aaron Copland’s “What to Listen for in Music” is, well, nice.
In the former category (excellent), is a book by Julian Johnson (British composer and musicologist) entitled “Who Needs Classical Music?” He makes a compelling case for classical music, based on the discursive nature of the genre, as well as the cultural and class assumptions, many of which he rips to shreds in true Socratic fashion.
This book is highly recommended based on Johnson’s deep, articulate, and accessible, forays into aesthetics, culture, and classical music. The analogies (“music=language”) stretch the arguments a little too far for my tastes, but that is a subjective criticism, and does not detract in any way from what I consider to be one of the finest books I have read on this topic.