... Well, maybe not completely different, but music that you most likely haven't heard.
It's been a long time since pop music has been a unifying force for an entire generation (or two, or three). Now there are too many genres, too many listeners with too many tastes, too many subcultures, too many niches (it's like the Web, no?).
For myself, I listen to a wide variety of stuff but not nearly as much new music, either pop or alternative, or hip-hop or whatever, than I used to when I was a rockcrit. I do my share of iTunes downloads, and back in the halcyon early Napster days, I did my share of file-sharing (or stealing, I know, I know). Most of the music I seek out these days, however, is music within proscribed genres like jazz, world music, blues, "Americana," singer-songwriters or -- gulp -- crass baby-boomer oldies. I seek out very few new bands unless someone recommends an act to me.
I manage to keep somewhat current by listening to some music that's offered online for free (and copyright free). Here are three sources downloadable via RSS feeds.