The majority are street musicians I think, especially Grandpa Elliot and Washboard Chaz.

There are a bunch of other videos by the same organization. This is "Don't Worry" (http://www.youtube.com/watch?v=tAjFnJuk1Aw&feature=PlayList&p=C122061BDC373B4B&playnext=1&playnext_from=PL&index=1) and there is "One Love (http://www.youtube.com/watch?v=4xjPODksI08&feature=PlayList&p=C122061BDC373B4B&index=2)" and some others