You can click on this map to expand it into readability status, and most of the bands I like are covered. I would add Ride to Oxford and I would delete The Police from London; Sting was from Newcastle, Andy Summers was raised in Bournemouth, and they were transplanted Londoners with a globe-trotting American in the mix anyway.
I would expand this effort so as to find a way to put most of the indie bands on a separate map. You could divide this into 50s-80s and 90s-present as well; a separate map of Britain detailing heavy metal would also be a good idea.
But, overall, what a great map.