every so often is the same thing all over again
right now, more and more people are growing tired of the current trends in music, both in pop and rock genres, while pop tends to be more commercially produced, rock goes through much more elaborated cycles:
you see, all the bands you see today seem to be coming from a music school that became mainstream more or less 15 years ago, right now we are suffering from "grunge fatigue", which is something similar to what was happening in music 17 years ago
back in the early 90's the music scenery had to change, mostly because the rock tendencies that had started in the mid 70's (Led Zep, Black Sabbath, Thin Lizzy, etc) had degraded into a mere shadow of all that energy by the late 80's (Faster Pussycat, Motley Crue, Poison)
but in the early 90's, alternative music, or grunge, as it was called came into the limelight (Nirvana, Pearl Jam, Alice In Chains, Soundgarden), all these new acts really had nothing new to them, just that they were labeled as "college radio" music
all the while, the bands that would influence the next fad 10 years later were releasing underground albums to little or no comercial acclaim (Slint, Jawbreaker, Sunny Day Real Estate)
you see, it's all cyclical, it's not that today's music is crap and everything that's been done before was better, it's just that something new comes up (which was never new in the first place), it explodes, becomes big, then in becomes too big for it's own good, then it becomes a fad, then you see new bands taking on these "new" sounds, thus watering down the overall quality, then there's a new musical explosion that bring something new, which eventually ends up becoming the stinky stiff by the door (or in this case, the cd's you bought back in college/high school/mid school)
the only difference, is that now trends seem to come and go faster and there's really nothing that has achieved true staying power
to prove my point
late 91: Nirvana's smell like teen spirit becomes a hit
early 92: all the grunge movement becomes huge
93: all this "alternative" culture seeps into the mainstream, suddenly we have pop acts with an "alternative" edge to them, people felt as if were the 60's all over again, minus, the free sex and mind altering drugs
94: Kurt Cobain shoots himself, grunge deflates soonafter
95: grunge is becoming too big for it's own good
96: metal music is all but "dead", guitar solos are taken away from rock, yet all this alternative/back to basics stuff is starting to become too tired
97: electronic music is the new grunge, kids trade their dock marteeens for glowsticks and their pot for X, the chemical brothers, daft punk and the like explode
98: pop ****s music in the ass
99: numetal arrives, and all the solos are still forgottten
2000: the world didn't end, electronic music is becoming too tired, now it's either you listen to n'sync and britney spears or you listen to korn and limp bizkit
I could go on but I think you get the idea