One of my points was the lack of promotion and/or sign posting of traditional music particulalry in London. I'll admit that if I had heard one more rendition of Whiskey in the Jar I would have probably run out in the street screaming!!
Whether or not what is being played is truly representative of traditional Irish music is another issue... but the majority of what I heard were traditional tunes and songs. And it was accessible, and folk music is part of the overall visitor experience.
In London, unless a visiter is a hard-core folky and knows where to look, traditional/folk song an music is outside of the visitor package.