There's a lot that's different about the two dances, of course, mainly having to do with the cultural oppositions of the 1960s and the 21st century. Verdon and her two dancemates were dressed in pastel pants suits. The television clip is in color (the hip way to go at the time); the accompanying music has a gentle, swinging-60s go-go beat; and the ladies smile at the camera. The song "Single Ladies (Put a Ring on It)," meanwhile, has a percussive, insistent sound to it. Beyoncé and company are shot in stark black and white (the hip way to go at present), and are dressed in high heels and revealing leotards; and the women cast an independent, collective scowl at the camera.

Beyond that, however, the signature Fosse moves are evident — the sexual hip-shaking, the come-hither facial expressions, the isolated body movements. "There's no new step under the sun," observed Margery Beddow, a former Fosse dancer and author of the book, "Bob Fosse's Broadway."

According to Butler, Beyoncé came to see fellow music star Usher when he appeared in Chicago in 2006, so she was familiar with Fosse's work when, early in 2008, she caught a YouTube video which set "Mexican Breakfast" to "Walk It Out," a hit by R&B/rap artist DJ Unk.  

	Gwen Verdon in "Mexican Breakfast"

The Verdon dance "was all in one take," Beyoncé explained in a later television interview, after many viewers and critics had picked up on the similarities between "Single Ladies" and "Mexican Breakfast." "And I thought, wow, how amazing would that be now? Because videos now have so many cuts, so many takes. Just to see a non-stop dance video, one take, all the way through, very simple. It was the [most] tiring thing I've ever done in my life. Because, if you mess us, you have to start over from the beginning." The video was shot in Brooklyn over the course of a 12-hour day.

"Single Ladies (Put a Ring on It)" wasn't the first time the singer had dipped into the Fosse library, either. Butler points out that she borrowed the dance sequence "The Frug" from the film of Sweet Charity and planted it in her 2007 "Get Me Bodied" video. (One thing's for sure: if Beyoncé ever follows Usher's example and takes a turn in Chicago, Butler won't have to start from scratch with her.)

Perhaps more than any choreographer in American theatre history, Bob Fosse continues to influence dance trends in the world of popular music and music videos. The video to Paul Abdul's 1988 hit single "Cold Hearted" was inspired by Fosse's erotica dance sequence from the movie "All That Jazz." And the video Pussycat Dolls hit "Buttons" is infused with the Fosse dance style — particularly, according to Butler, "Big Spender" from Sweet Charity.

Bulter claims that Fosse would probably not have been upset by such outright homages. "Bob did the same thing in reverse," he said. "He'd pull from theses old social dances like the Black Bottom and it became part of his vocabulary."

While Beddow is happy that the Fosse influence lives on, she feels like something is being lost in translation.

"Fosse would appreciate the fact that they're beautiful and are looking very sexy," she said of the "Single Ladies" video. But "they really needed to go a bit deeper into what Fosse's style was. The point of his work was it was all about acting. Whether you're singing and dancing, you're acting. You're in the business of communicating ideas. Fosse had a subtext to the steps, so that you would be doing something with your hips, but with your eyes and your head, you're thinking 'How do you like this?' Something would be challenging, something would be 'Ha, ha, ha. I’m going to walk away now.' There was something you were thinking in each section."

Beddow said she could see that Beyoncé and her companions "were thinking sexy, but it was one color. Fosse always said the head and the eyes develop last. They look out at the audience. They're landing it on the audience.

"He said, 'If a dancer isn't also an actor, it's just so much animated wallpaper.'"