i think has to do with the executives personally. refeing to sabbyxx post he has a point truth being knowing the executives in the 50s and the 60s had the attitude if it sells it sells and puts it out even without understanding it even if its strange music to them personally. it was better with those guys in charge. the guys who replaced them in the 70s were more conservitive than the guys then reason they got hired was in the 60s they were like lets get hippy he might know who to take a chance with they get a hippy just to bring there coffee in sooner or later they give him a job now hes in control hes like we can't take chances on this group i know cause "am really into music" 80s i would say on a fraction of of the music there was exceptional most of it was like flavor of the month. hip hop being a new thing started into positivity later mutating into a farce which is all about b**ches guns and bling. the 90s they found it was cheaper to manufactor bands like mcdonnolds creating music with inoffensive lyrics and pin up guys or women to get the impressonable teens to part with there money. 2000s it turned into a musical cespool i call musical incest when no new ideas are introduced leads to musical inbreeding. also instant stardom is introduced in the 2000s instead of earning it by honeing your art u go on a talent show and that is stardom acheved. in conclusion without deveation from normal standards progress is not possible looks at 50s 60s 70s u can hear lots of deveation from the norm 80s barely any 90s just a scrape 2000 just a scrape.with the way music is manufactured a vast majority people cannot look beyond the top 40. any way this is just my opinion.