During the 20 century people seemed to like rock and metal, there were great bands like Guns n' Roses, Nirvana, Slayer, Metallica and before these bands there were Rolling Stones, The Beatles, Led Zeppelins, it seemed that people liked these bands a lot and the others I mentioned, it was like a flow which didn't stop, then at the end of 20th century punk/grunge became famous, people were liking those two types of genres too. At the beginning of the 21th century, people started to like pop/rap/RnB and they stopped listening to these kind of music! I really don't know why they did it but do you think pop/rap/RnB are better than rock/punk/grunge/metal? Personally I think that pop/rap/RnB ARE rubbish music, it's not worth of listening to them, they aren't even close to rock/punk/grunge/metal!