Most music appreciation textbooks that I have reviewed usually approach it from a music history "lite" approach which, imo, deadly boring for normal non-musical students. The Musical Experience approaches music appreciation from a genre-based standpoint. After an introductory chapter, the remainder of the chapters cover specific genres, e.g., Music for the Religious Experience, Music for the Stage, Music for Dance, Songs, etc. The students still get the appropriate historical information in each chapter but it makes it much easier for students to grasp the relationship between music of the Baroque or Classical style periods and contemporary music for the same genre.
Although marketed as a higher ed textbook, I believe it would be appropriate for high school students. It is an expensive book, ~$95-$100, and is unlikely to be on the state textbook list. However, I believe it is an outstanding book.