Levon Helm played drums and mandolin, and sings some of the songs. I never realised he had a low opinion of the concert, but more really of the Martin Scorsese film of it, which I've never actually seen.
Levon Helm was born in Arkansas, grew up in a town called Turkey Scratch, and was apparently inspired to music by the mandolin god Bill Monroe who he saw at age six. (Here's Monroe that year: you can hear the connection.)
I think "Jemima Surrender" is the only major Band song he wrote, but he sang the most well-loved ones, including "The Weight" and "The Night They Drove Ol' Dixie Down". Here's a couple of his tracks, the second from his brilliant last album Electric Dirt.