If you notice closely, Ben was playing a 'cigar box' guitar, although he alternated with 4 other guitars and a fiddle. He performed kind of a blue grass-country-gospel style sound for 2 hours straight - and that included, picking, singing, playing the bass drum with his right foot and a snare drum with his left and I don't know what he was using to play the symbol. Anyway he constantly drew a large crowd and that boot on top of the bass drum took on quite a few bucks.
Check out more Street Bands at: http://vimeo.com/moogaloop.swf?clip_id=2539741