Don't know if this has been shared already, I just ran across it & a search didn't find anything. John & Larry jamming 'John Henry' for about a minute. They were great together, wish they had made a duo recording. Click on the image & a video plays.
http://main.wgbh.org/saybrother/programs/sb_0318.html
http://main.wgbh.org/saybrother/programs/sb_0318.html