It did bug me how he was making the low percussion sounds. Almost a bass drum feel. I was so afraid he was cheating…
Nope. On his THE MIDDLE (Minor Key Version), he slows and adds depth to “That theme from a Target ad”.
You can see him stomping on a piece of wood at 1:11 (closeup at 2:48). Sure, he’s not making the sound with his mouth, but I saw the legendary John Hartford playing three instruments at once and dancing on a piece of plywood to add percussion.