When John Mellencamp played his hit "Pink Houses," he mentioned that that song had been inspired by artists who came before him who tried to make a difference with music. "When I was growing up, my parents used to play his records, and I thought, 'Wow, maybe I could do this someday. Ladies and gentlemen, Pete Seeger!"

The folk music icon then took the stage, armed with his banjo. "Friends, at age 94, I don't have much voice left. But here's a song I think you know, and if you sing it, why, we'll make a good sound!"