The opening paragraph from Daniel J. Levitin's This Is Your Brain on Music: The Science of Human Obsession.
What is music? To many, "music" can only mean the great masters - Beethoven, Debussy, and Mozart. To others, "music" is Busta Rhymes, Dr. Dre, and Moby. To one of my saxophone teachers at Berklee College of Music - and to legions of "traditional jazz" aficionados - anything made before 1940 or after 1960 isn't really music at all. I had friends when I was a kid in the sixties who used to come over to my house to listen to the Monkees because their parents forbade them to listen to anything but classical music, and others whose parents would only let them listen to and sing religious hymns, in both cases fearing the "dangerous rhythms" of rock and roll. When Bob Dylan dared to play an electric guitar at the Newport Folk Festival in 1965, people walked out and many of those who stayed, booed. The Catholic Church banned music that contained polyphony (more than one musical part playing at a time), fearing that it would cause people to doubt the unity of God. The church also banned the musical interval of an augmented fourth, the distance between C and F-sharp and also known at the tritone (the interval in Leonard Bernstein's West Side Story when Tony sings the name "Maria"). This interval was considered so dissonant that it must have been the work of Lucifer, and so the church named it Diablolus in musica. It was the pitch that had the medieval church in an uproar. And it was the timbre that got Dylan booed. It was the latent African rhythms in rock that frightened white suburban parents, perhaps fearful that the beat would induce a permanent, mind-altering trance in their innocent children. What are rhythm, pitch, and timbre - are they merely ways of describing different mechanical aspects of a song, or do they have a deeper, neurological basis? Are all of these elements necessary?