Holy crap.

Somehow I missed this. It's "This Land Is Your Land," played by Pete Seeger and Bruce Springsteen at The Obama Inaugural Celebration Concert. I found it via Mark Evanier, who writes:

Seeger is 89 years old. He was close to half that age when I saw him at the Santa Monica Civic. This was back when they still had segregated schools in parts of the South. I wonder what his response would have been if someone had said to him then, "You'll live long enough to sing that song on the steps of the Lincoln Memorial as America inaugurates a black man as President of the United States."

And as if that's not cosmic enough, George-bloody-Lucas can be seen at one point singing and bouncing along.