Certainly Joplin wasn’t.

[Laughs.] No, she was just wonderful.

How did you pick your set list?

I’ve run into this before, like at Live Aid. What do I sing? Not everybody knows me, and my music isn’t rock ’n’ roll. So at Woodstock, I did “Swing Low, Sweet Chariot,” which was a showstopper. I knew that would “work.” Richie Havens, who opened the show, was somewhere in between. He was a folk singer but he rocked out. If I could’ve rocked, I would have!

During your first song, you said brusquely, “Sit down, please” to the crowd. Do you remember why?

You mean I said please? [Laughs.] I was kind of a shrew. They were sliding around in the mud and having a good time. In rock ’n’ roll, nobody cares if people are listening. I cared. I was always like that, even playing the coffee shops. In the early days, say at Club 47 [in Cambridge, Mass.], they came there to play chess and talk. And I wouldn’t tolerate anybody turning the page of a book! Seriously.

The way you describe yourself, it’s almost as if you thought you were priggish.

That’s a good word. I was also deathly shy, and I’m sure I had stage fright.

[See all of our coverage of Woodstock at 50.]

You were the first of three acts who sang Bob Dylan’s “I Shall Be Released” at the festival. What was it about that song that resonated so strongly at the time?

Dylan’s stuff is still the best we have. There are a lot of great songwriters, but pretty much everybody pales next to what he cranked out. So it was partly because people could sing that song. You couldn’t sing all of what he wrote, nor what other people wrote. I guess it’s anthemic. And that’s the trick. A lot of people write good songs, but when you need an anthem, we’re still going back to music from way back then.

You went on at about 3 a.m., finished at 4 a.m., and then stayed for the rest of the festival. Do you have any specific memories of being backstage for all three days?