I have a little band with a 25 year old singer-the rest of us are 41-46.when we play shows,we get her 20 something crowd and our 40 something crowd.It seems to be working for now.We are kind of modelled after the band Garbage I guess,although we sound nothing like them!I think that it's really up to your own state of mind.I recently saw Agent Orange at a local dive bar here in Van.They rocked hard and the kids in the crowd didn't seem to mind that the band were as old as me ! If you are honest about the music/feel you are trying to convey, the kids will pick up on that and judge you accordingly(I hope!)