It's interesting to note that every generation has a musical standard that really caries it. In the 60's it was British Rock and Roll, Folk music, and Motown. Then in the 70's it was Pop, Rock and Disco. The 80's were defined by a spectrum of different genres, New Wave, Alternative and Hip Hop began to come to the scene. As well as the Hair Metal bands (Oh I want to forget). The 90's were characterized by Grunge, Gangster Rap, the Revival of Pop Girl and Boy Bands (Spice girls and N'Sync?), and the rise of the alternative/indie scene.
So the last decade 2000-2009 was really characterized by a uniqueness of variety but at the same time, mainstream music that was really "Hip Hop based", granted the boy band thing was a commodity but it never withstood the entire decade. Yes R&B was an important part of the decade, as well as the early decade Garage Revival. However, the decade is best summed up by hip hop.
Now however since the rise of the "Disney" "bubblegum pop" revival, it seems like this entire Hip Hop Culture is beginning to become silenced. No I for one, like some hip hop, but personally the genre with few exceptions (Jay Z, Kanye, and Outkast) has become quite boring. Not to mention the attack on Hip Hop videos in 2005 by Oprah really changed the game for Hip Hop, allowing the incarnation of "Bubblegum pop."
So who is the fore-front? None other then the Disney Channel all-stars, Miley Cyrus, Taylor Swift, the Jonas Brothers, Justin Bieber, blah, blah.....They've created a teen culture where they have been able to apply to the pretween demographic, as well as infiltrate the internet (Go on youtube and see who has the top videos). In Essence changing the entire fabric of the music industry.
The Tween influence is felt on the charts, radio-play, and even in pop culture references. These people sell. Granted they are given more freedom then some boy-banders in that they are able to play their own instruments. Yet it's just a manufactured part, nothing original or exciting. It's just kids trying to be grown-ups.
Mediocrity is at the center of this issue, as well as the fact that "Sex Appeal" sells. I mean look at it, after the Jonas Brothers hit that late 20's to early 30 mark their done, same thing with Miley Cyrus. In fact there are subtle hints the Jonas Brothers are Miley Cyrus done, with the rise of "Justin Bieber." Practically the marketing of starts has become younger and younger, and the quality has become worse.
If It weren't for the internet, we'd all be screwed. Man we need another musical revolution.