Quora Answer : If you could put all music into 3 genre categories, what would they be?
Music which is fundamentally about the composer. What they wish to express by the careful putting of notes and sounds together. Elaborate structure and subtle effects. This music includes much classical symphonic composition. But also electronic music painstakingly put together in the studio.
Music which is fundamentally about the performer. What they wish to express by putting their bodies up in front of a live audience and moving, twisting, vocalizing, dressing up in funny clothes etc. Many rock bands fall into this category. As do jazz improvisers. Rappers hyping a crowd. And solos for classical virtuosos.
Music which is fundamentally about the audience. Music which serves their needs. To create a soundtrack to dancing or smooching or resonating with their heartbreak. Much disco, EDM, pop music etc. falls into this category. But also military marching bands. Sea shanties etc.