Re post 3, most trains between London and York take between 2 hrs and 2 hrs 15 mins. The coach is about 5 hours 30 minutes. However I don't know anything about the live music scene in York ...
Whoops, you're totally right! I failed to mention the stressful and delayed travel I had. The train only took about five hours because it got held up in a few cities along the way. But since its only 2hours more the reason for Texasguitar to consider York for his stay in the UK!
I agree with Dodger. I've lived in Brighton on and off more most of the past 15 years, I live there now, and I'm happy to confirm that Cyberia's friend is talking total and utter rubbish. Anybody who feels the need to carry a knife around in Brighton is a total idiot.
Texasguitar, Brighton would be an excellent choice that meets all your requirements, but check out Bournemouth too. Also maybe Bristol, though it is a little bit bigger.
I'd say Reading- it's a town, which isn't too huge (still fairly big, not sure of population), has a good music scene (Reading Festival, clubs and other music venues in the centre of town), lots of shops and restaurants, a large museum, and it's about an hour away from London- the train station is in the centre of town, so it's easy to get around.