I've read this thread through and I thought I'll reply as I am 1000% part of the generation you are talking about...
I hope you don't mind if I write a few words about myself: I am 18 years old and I love music just as much as pool - the two things (along with girls of course but that's a different story) that can switch me perfectly OFF. When I'm listening to my favourite musics or when I'm down playing pool 8 or 9 in the morning on Saturdays (that's the only time I can go and play) I'm thinking about absolutely nothing but pool or just thinking about whatever I want while I'm listening to Indie (a kind of rock music to describe it..), or Drum&Bass or even Jazz (I love big-band, acid and bebop the most).
Sometimes I'm wearing a coat and look as elegant as I can (I love wearing elegant clothes) and sometimes I wear my pants under my rear end. It depends on where and who I am with.
As for pool and poolhalls: I've been playing pool since I was 15 and more seriously for the last 1.5 years... I love this game and I always show the biggest respect I can for all the players that are older (and therefore way more experienced) than me and I am always exceedingly thankful if any of them helps me with my game, tells me a little secret that they use or anything like that...
And whenever I get to a poolhall I do care about music - I love almost all kinds of music (9 out of ten at least) so it doesn't really matter what is on in the background... and as for the volume: it can set me up when I can't hear my own voice from the music... If I want loud music I'll go to a place where I can party, where I can shout as loud as I can, etc. but not in a poolhall...
...but here comes a little twist: let's imagine me, playing pool with some older (30 and 40+) friends of mine in a poolhall, my pants are low as hell - and I suppose that they think that it is ridicolous they understand it because they can think back that they were just ridicolous as I am now (I do NOT wish to imply with this and this is definitely not only for you, 3andstop, this is a fact) and the music is just too loud... If that would be the case than me and my low pants would go there to the counter and ask the person behind it to turn it down. After that I wouldn't care for all the youngsters that would come over to me, I'd say to them that: "Hey, I am just like you (I even look similar with these outrageous clothes) and if I want to listen LOUD music than I'd go to... (and I'd name a few places where they could party)"
That's it, despite of my (eventually) idiot-like clothing I love pool, I love and respect all the players that are certainly WAY better than me and I'll try to (and I do!) help everyone, who knows even less about the game than I do. What is more is that I am lucky enough to say that I have lots of friends from all the ages (ranging from 20 to 50+), they're very helpful and I'm again very lucky to say that they're: my friends. (despite of my look - eventhough I look very considerately in 99% of the times when I go to play pool).
That is my .02 for all this, I hope all of you understand me... Of course I am opened and ready to hear all kinds of suggestions regarding all that let that be positive or very negative.