The great thing is that there's a lot of pop/rock music about at the moment that can be taken to a session and played on acoustic guitar -- Oasis, Travis, Stereophonics, Coldplay etc... My teenage boys thankfully have very catholic tastes, but these are the bands they turn to for working out chords and playing along. They grew up mostly listening to whatever I did, particularly in the car, which covered a lot of ground (the music, not the car), but leaned heavily towards Neil Young, James Taylor, Steve Earle kind of stuff, and that feel for melody and acoustic guitar stuck with them. A couple of months ago we were listening to the radio in the car when a James Taylor song came on being sung by someone else. I vaguly recognised the song, but it wasn't one of the better known ones that my kids might have heard, and I was so proud when Michael (13) said 'this sounds like it could have been written by James Taylor'. I guess what I'm rambling on about is that I agree with IanB that music keeps you young, but it helps if you've got a couple of teenage kids who can introduce you to their tastes!