I AM... SASHA FIERCE!

By now you should know Beyoncé's infectious tune by heart. It's the get-the-party-started anthem of the year, the fun kiss-off track that got Justin Timberlake dancing in a leotard on SNL, The Chipettes shaking their hips in Alvin and the Chipmunks: The Squeakquel and fans of every age, shape and size posting tributes to YouTube.

Nominated for three Grammys, Beyoncé's hit "Single Ladies (Put a Ring on It)," from her third solo album, I Am ... Sasha Fierce, has taken the world by storm. Peaking at No. 1 on the Billboard chart and staying on top for four non-consecutive weeks, the single dominated Hot 100 Airplay, topped U.K., Canadian and Australian charts and, with over 3,000,000 digital downloads, became the singer's highest-selling song.

But do you know the story behind the music and the moves?

The Lyrics

"Single Ladies," conceptualized by singer-songwriter The-Dream, was recorded after Beyoncé secretly married Jay-Z.

"It was the only public statement that they ever made about marriage," says the song's producer Christopher "Tricky" Stewart. "When we went into the studio she didn't have a ring on or anything, because at that point they were still really hiding it. That's where Dream got that concept from."

"I thought it was a subject that most women wanted to talk about because most of us men are scared as s--- to be bound to a commitment," adds The-Dream (real name: Terius Youngdell Nash).

The Sound

Ever notice that "Single Ladies" sounds a lot like another Beyoncé dance hit, "Get Me Bodied?"

"I always believe that every artist has a groove to them," says Tricky, who crafted the song's shuffle beat. "That rhythm is what she responds to," he adds. And once she had the rhythm locked in, she delivered the now-classic lines, "on point right away," says vocal producer Kuk Harrell. "She knows what she's going for."

The Video

Spawning a massive dance craze and hundreds of YouTube tributes, the moves in the music video for "Single Ladies" were choreographed by Frank Gatson Jr. and JaQuel Knight.

"She wanted it to feel good and powerful and she wanted something that everyone would do," says Knight. Beyoncé's main inspiration was the Bob Fosse-choreographed performance of "Mexican Breakfast" on The Ed Sullivan Show in 1969 and, says Gatson, "Shirley MacLaine in Sweet Charity ... That is why Beyoncé ran up the wall [in the video]."

Pair those moves and killer costumes, "reminiscent of the high-cut leotards seen in both A Chorus Line and All That Jazz, but modern," according to designer Tina Knowles, and add a flash of that $5-million Lorraine Schwartz wedding ring, and it's easy to see why "Single Ladies" became an instant classic.

"I think the visual is what really pulled the record together as a whole," says Tricky. "The reach was just unparalleled."

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