Music in the Mainstream

Our parents fondly remember their childhood- the golden age of suburban paradise, where Beaver and his buddies frolicked from sun-up to sun-down with nary a protest from their mothers. Music came from the school of squeaky clean- so much so that "I Want to Hold Your Hand" was a shocking declaration that turned many a community upside down.
Then came the Age of Free Love, where psychedelic lyrics that could mean whatever you wanted them to reigned supreme. "Afternoon Delight" was just an ice cream cone, right? There were no music videos to tell the public otherwise.
The 80s brought heavy metal and androgynous male singers to the forefront of the music movement. Lyrics were often socially charged and music was either LOUD or laughably synthesized (sometimes both!). The sole survivor of the cleaner music of the past was Billy Joel, as everyone else was busy experimenting with new instruments, sounds, and looks. "Video Killed the Radio Star" premiered on MTV. Oddly prophetic, doncha' think?
The early 90s were dominated by grunge and the beginnings of hip-hop, while the late 90s were a sensualized throwback to more innocent times- the music itself wasn't terribly offensive, but the vids were pretty provocative (coughgagBritneygagcough). Music in the mainstream wasn't terribly diversified...yet.
Somewhere around the turn of the century (or millenium, if you like) something funny happened. Everything became mainstream. The top ten albums of the (pre-Ipod) 2000s were made by the Beatles, Norah Jones, Eminem (x2) , Britney Spears, Linkin Park, N'Sync, Avril Lavigne, Usher, and Evanescence. The cleaner genres of the past came back with a vengeance, but so did bubble-gum pop, rap, hip-hop, R&B, rock, punk, and whatever you call Evanescence.
Prime example of this: Dick Clark's Rockin' New Year's Eve '07. I was sitting on the couch around midnight, listening to "the most influential artists of 2007". First came Tom Higgenson singing "Hey There Delilah", which is pretty much the sweetest, cleanest song ever written. Then came Akon, with his hit song that I unfortunately do not remember the name of, BUT I can tell you that the centerpiece of the song was "I'm a gonna F--- U, I'm a gonna F--- U" repeated over and over again. Sorry, I'm not a huge Akon fan.
The point that I'm trying to make here is, well, in what sort of crazy universe are Akon and the Plain White T's both accepted members of the mainstream? The whole point of a mainstream is that there's one MAIN style of music or clothing or whatever that dominates pop culture. Maybe there's a mainstream of heavy metal with a strong undercurrent of synth-pop, like in the 80s, but having the absolute extremes of music both in the spotlight at the same time? That's new.
I can give you a whole list of artists with virtually nothing in common that are (or were) mainstream at some point. For starters, Green Day, Usher, No Doubt, Justin Timberlake, Beyonce, The White Stripes, Pink, Taylor Swife, Norah Jones, Amy Winehouse, Panic! at the Disco, etc.
I guess you can say that the music world is just mirroring what's happening in society. Extremes of obesity and anorexia, Democrat and Republican, and fundamentalist and aetheist are all parts of our generation's "mainstream".
Welcome to America.