The other day I was doing some YouTube surfing of old dance performances. But try as I might, I was unable to find a tape of one of my favorites, Dudley Williams of the Alvin Ailey Dance company doing the “Rocka My Soul” excerpt from Ailey’s masterpiece “Revelations.”

I’d hate to think that Williams’ ebullient, exuberant yet understated performance is lost to antiquity. I’ve seen many younger dancers try to fill his shoes, but they just can’t, no matter how hard they try.

The following clip of Williams will have to do instead for now. It’s from a different portion of the same piece, his solo “I Want To Be Ready. Williams, a man whose skinny frame belied his considerable strength, didn’t retire from performing until the extremely advanced (in dance years) age of 66, and the YouTube clip I’m about to offer here shows him in his later years, when his technique had diminished considerably.

But Williams was never really about technique. Here’s what he had to say about “I Want To Be Ready,” and about performing itself:

“Revelations” is credited to Ailey, but “I Want to Be Ready” was actually choreographed by James Truitte, an Ailey dancer who, like his boss, had studied with the California dance guru Lester Horton. Williams says the whole dance is just a Horton class exercise: “It’s a coccyx balance””laterals, hinges, laterals, hinges.” In Truitte’s hands, however, it became a dance. When he taught it to Williams, he told him how it was supposed to feel: “He said, ”˜When you start, it’s like someone is on your shoulder, and pushes you back down. You try again, and you go a little higher, and they push you down. You try again, you go higher, and you break out.’ ”

Williams radiates calm onstage, but he says he is a very nervous performer: “I sweat in the palms of my hands””I wish the theatre would burn down.” He sees this as part of the process. “Dancing is about acting, about being a liar, basically,” he says. “Because often you don’t feel like dancing, but it’s your job. So you get out there and you do the movement, and it’s not happening. So you work harder, you work harder, you go deep inside what you’re about.” And what started as an act becomes a reality.

Williams was always ready.