Today, little is different. Britney/Backstreet Boys/Destiny's Child etc. amount disco. Creed, Vertical horizon, Linkin Park, etc. amount to Rock and Roll. And everything is still about marketing.
This excellent article in Newsweek of all places says it all pretty well. Also makes the point that there is good stuff out there but you gotta dig.
This is something I didn't realize:
If your “local” top 40 radio station (which may now play only 25 songs) isn’t owned by Clear Channel (which has nearly 1,200 stations in the United States), it’s probably owned by Viacom (a mere 186, but it also owns MTV, which owns the hearts and minds of millions of teenagers).If anything that is a good omen for satellite radio like XM and Sirius .
Such stations, as identical as Gap stores and McDonald’s franchises, exist not to turn you on to cool new music, but to keep you from turning them off before the commercials; that’s why the stuff they play is so robotic and formulaic.