UK!
Classic Rock only becomes so as the tide of time passes by, I wonder how much 'modern' rock will stand?
Although I put UK, I do really like a bit of Focus to run to, but they are only a short ferry ride away...
And onelifecrisis got it right with the answer to life, the universe and everything - 42 years ago, Led Zeppelin performed for the first time as The New Yardbirds, Dave Gilmore joined Pink Floyd (thank goodness!), The Beatles released "The White Album", Yes/Deep Purple/Cream formed, as did Black Sabbath (as Earth).
