I heard them on the radio, and then about 45 minutes later I was in Wells and there were two tanned traveller-like 20-something chaps, one with the requisite wispy beard (but no dog on a string), busking traditional acapella songs in the market square (it's market day*). Very good they were too, I thought. They consulted a small fat little grey book for ideas of what to sing next but otherwise but appeared to be word perfect from a big memorised store of songs.
Here's a pic of them: www dot nawaller dot com/singerssm.jpg though it won't be there for ever.
*Wells market square was one of the locations for the violent showdown in Hot Fuzz, if anyone has seen it.