How to save a friend from metal rock

What would you answer if someone—an Indian friend, for instance—asked you for a sort of introduction to Western music? And how would you act if you were willing to save him from metal rock? Well, you might want to explain to him that one of the characteristics of Western music is polyphony, and that this whole thing, of combining different melodies together, began in the Middle Ages, possibly by chance, and progressed in the subsequent centuries. Then you might want to tell him that Western music can also be monodic, the opposite of polyphonic … Or you might want to take a look at this post “before” giving a definitive answer. The latter is the option I would recommend ... ;-)