When I was 16-20 I was listening to Cream, Led Zeppelin, CSN, Pink Floyd et al and I just can't listen to that stuff any more having been overexposed to "Classic Rock" radio in situations I had no control over (I do make an exceptions for The Band and the Grateful Dead though)'

In recent years there has been so much good music being written and performed by artists like   Blind Pilot, The Shins, Local Natives, Gutcher, Dave Rawlings Machine, Ya Lo Tengo, Fountains of Wayne, Gregory Alan Issakov, Fastball, The Old Crow Medicine Show, Trampled by Turtles, Lindsay Lou and the Flatbellys, Earl, I'm With Her, Cass McCombs, Mandolin Orange, Crooked Still, Nora Jane Struthers, The Fleet Foxes, Willie Watson, The Little Willies, Chance McCoy etc. from strictly acoustic to electronic and distorted and points in between.

If you're not digging any deeper than Justin Beiber and Katy Perry of course you're going to find modern music wanting.