I think, to be fair to Spanky, he/she (just who are you, Spanky? You seem to know me....) referred to London itself. It's true there are a number of bands inside the M25, but the capital itself (I suppose, if you define it by the 'train zones' is not flush with bands.
I disagree with the point made earlier that 'Brass instrument playing isn't quite as common as in the more northern parts of the country... ' It is, I feel, but there is perhaps more of a tradition to start out in the orchestral field (trumpets and French horns again!) I distinctly remember being told by my music (as opposed to trumpet) teacher to 'steer clear of brass bands' (He didn't, as I recall, say why!)
Also, the sense of community in London is dwindling, maybe it's even been totally eradicated, who knows? (Another reason I can't wait to get out in October - having said that, Fulham, with its mix of people from all over the world, Japan, New Zealand, Australia, Croydon ;-).... must be one of the most welcoming and friendly bands around. Gonna miss 'em!)It really is, 'each for their own'. That coupled with the numerous distractions in the capital like pubs, clubs, cinemas etc. (Other cities have these of course but have a better sense of community) means banding doesn't really feature high on potential players' lists. Though I think that in a way, if we could get more bands to start up in London, it might just kick start the idea of getting a sense of community back!