have watched my 19 year-old daughter and her friends sample countless bands on Napster and Kazaa and, enthusiastic for their music, go out to purchase CDs. My daughter now owns more CDs than I have collected in a lifetime of less exploratory listening. What's more, she has introduced me to her favorite music, and I too have bought CDs as a result. And no, she isn't downloading Britney Spears, but forgotten bands from the 60s, 70s, 80s, and 90s, as well as their musical forebears in other genres.
A little too anecdotal, why?
That's about the time of life when you go for greater exposure in general. College folks maybe exposed to stuff in dorms, working stiffs hear stuff from a wider variety of coworkers.
The dorm is often a big cross-pollination arena -- the kid with the guitar down the hall turns you on to Robert Johnson, you figure out how to use a bong, you actually look old enough to use your fake ID.
Musical exploration in late teens and early twenties is pretty much the default.
Does file sharing lead to more diverse musical tastes? I guess we can't really say without a controlled study.
Anecdotally, I haven't seen it. The demographics at places like Yoshi's hasn't changed.
19 year old's are in the middle of an "awakening"