As a composer and pianist noteworthy enough to be mentioned in his own book, Stevenson approaches western music as an active interpreter of the tradition and a partisan in some of the controversies he describes. The result is a polemical account of the music's origins (ritual magic, etc.) to present day ""serial"" and ""aleatoric"" compositions, with brief asides on the nature and influence of African and Eastern music, capped by a vigorous prediction of a future ""world music"" which will synthesize various national musics into a single, harmonious language. Stevenson also contends that music reflects man's natural and social environment, that the best music reflects it most accurately, that it ""shows these two elements of magic and labor in dialectical intercourse, in unity and struggle,"" so that Pavlovian style, it recreates feelings and moods via molecular reflexes. There are ""progressive"" composers like Liszt and ""reactionary"" ones, Brahms for example, whose work ""vacillated between impassioned pessimism and a sense of complacent well-being."" Programmatic music expresses ideas, it is rooted in reality, while absolute music is ""idealist"" and evolved from confused abstractions. Cultural nationalism, the folk songs of oppressed peoples and the popular composers all have their place in Stevenson's ideology as creative mainsprings for the music of the future. His style is dense, but the ground he covers is enormous and the best that most entries get is honorable mention. The musical illustrations are useful but often beyond the grasp of those whose theoretical preparation is limited. Compared to, say, Grout's A History of Western Music this introduction has only its politics to recommend it.