Don't they? I mean...I'm not saying they definitely do since I don't know for sure but... surely they must do? Surely it's similar now to how it always was...some kids aren't THAT deeply into music but some are REALLY into music. I just find it really hard to believe that teenagers no longer listen to music as much. Sure some of them spend too much time listening to One Direction or whatever (but it still counts as listening and I reckon many do that obsessively)... but still I bet a whole load get just as lost in new indie music, rock, metal, or whatever as any of us did. Round here it's rare to see a teenager without headphones on... they seem to listen non-stop, not just on their beds....and I think people share music now more than ever.
It's maybe true to say that an LP seems less special now, since it's likely a download with no sleeve to read through, and because it's one of SO many...somethings lost there... but gained in other ways.
I don't think teenagers will ever stop finding cool new music (or finding cool classics) and sharing that with friends, and being just as into it as any of us are/were.
Re magic years - I'm way beyond teens (WAY!!) but still find brilliant new music, both signed and unsigned (also agree with David... there's plenty here alone)... plus Soundcloud and similar are overflowing with creative original music.... the only sad thing is that not enough of that makes it out to the masses, record companies won't take the risks they used to ... and so the mainstream has a fair amount of manufactured crap in it, but it's out there for sure. And there's talent to rival the greats too ... but generally overlooked and not given the chance to be great. I suppose it's harder to be totally fresh now though...