Just curious what you consider "old people" music? Beatles/Kinks era, Michael Jackson/Police era, steve wonder/eagles, pogues/pink floyd. I actually have no idea of popular music for several decades. I didn't know where to find interesting music. I think I started again in the 90s
Anything before the 70's has a pretty distinct sound - live instruments and the like - but most decades of the past have a greater focus on music in pop culture than consumerism in pop culture that I think, starting with the 00's, has been the driving force behind pop music.
Like in the 90's, rebellion dominated the airwaves in the form of emerging hip-hop/rap artists (N.W.A winding down, TuPac stepping up, Biggie, Redman, RZA) and grunge/rock/punk artists (Nirvana, Pearl Jam, Radiohead), the 80's had alternative music that sort of kicked back at the 70's, moving away from psychedelia and into a more female-oriented sound with Madonna, Whitney Houston, etc., but also gave way to R.E.M. and hardcore punk that grounded most of what was to happen in the 90's (Black Flag, The Pixies, NIN). The 70's were all disco and European-influence glam-pop and although they focused on style a lot, it was all about love - The Bee Gees (R.I.P to all the fallen brothers, Andy especially), Abba, Wings - but they also had your rock/metal guys like Queen, Zeppelin, Sabbath, Pink Floyd and really early punk stuff. And then the 60's were all Stones and Beatles and Sex Pistols.
The oughts (as far as I can remember - most of my oughts music has been relegated to collecting dust on shelves) came with the emphasis on money and possessions and how much money and possessions could be bragged about in a three-minute song and emphasized hyper-sexuality over everything. Britney Spears, Christina Aguilera, the Disney kids all grown up (and some yet to grow up - Jonas Brothers, Miley Cyrus as Hannah Montana), Justin Timberlake, Chris Brown (deplorable human being), etc. And that era has sort of continued into this decade of music with a more electronica-oriented sound coming out now.
That's all in terms of popular music, of course. Every decade has great music, some just need more attention to find - Immortal Technique is a brilliant rap artist, Bon Iver is a fantastic artist in whatever genre he chooses to pursue, Brand New came around as a rock band and there are still a whole bunch of the usual suspects around to entertain, producing great music year after year even though a lot of public interest has waned.
The 'socially conscious rapper' is seeing a bit of a resurgence with Kendrick Lamar (his Taylor Swift feature and Taylor Swift changing from eloquent country music to pop both angered me to no end), J. Cole, etc... But yeah, generally popular music has moved from a sort of "The People's Music!"-focus to a "The Music That The People Will Buy Music!"-focus.
All this is subjective, though - those artists are just off the top of my head and some of them I don't even like (I really don't understand the musical appeal of Black Flag or, really, any of the really hardcore early punk bands) so this is just a really narrow view of popular music through my eyes.
>.> Sorry about how long-winded that got. I'm a bit of an Air-head.
I really should get a profile picture if I'm gonna keep doing these Tolkien-esque posts. XD
EDIT: OH! And anyone who's interested in soul, R&B or funk should check out Betty Wright and The Roots' album from a few years ago - The Movie. It's pure, unadulterated, old-school throwback music.