it all comes down to how you define 'underground', and thats a tricky one, it certainly is and indeed was mainstream in certain areas. Around Stoke NS was THE popular music of the mid to late 7ts, kids down my street used to do skipping to 'what' as well as the rollers chant, 'b- a- y, b-a-y' ect. Is it really mainstream in the true sense? I'm sure there's loads around the country who've never heard of it, especially amongst the young, who are probably far too busy getting tattoo'd over 90% of their carcass whilst high on a mix of mad cat and veno's. Is it underground? well even the most commercial side of it probably is, to a certain extent. Is it cool anymore? you seen any of those weekender photo's?
I sometimes catch the big band show on sundays evenings on R2, they advertise concerts by swing band's around the country, Cromer pier and the like, and I wonder about the 'big band scene', I'm sure its not cool, but its probably got more dignity than what's left of NS.