At first it seemed like a regular Saturday at The Galleria. Clicks of stilettos, swaying boutique-branded shopping bags and sociable chitchat dominated the scene, even as an increasingly inquisitive crowd gathered around the fountain in front of Macy's.

A stage decorated in happy pink with feathery poofs stood empty between two escalators. All the Twitter chatter pointed to something happening at noon-ish, implying a secret musical bacchanal.

Dressed in a sparkly skin tight black tunic with a flamboyant hot pink boa, Gloria Gaynor suddenly appeared from out of nowhere onto the stage and belted her definitive anthem, "I Will Survive." The thrilled audience, including this reporter, sang along — shouting every word — and let their best disco dance moves flow.

The one-and-only disco diva is undeniably connected to the sound of an arpeggiated piano chord giving way to the legendary lyrics, "First I was afraid, I was petrified."

The words echo sentiments of those diagnosed with cancer, beginning a fight that should end in the disease "walking out the door, not being welcomed anymore." So it was fitting that Gaynor accompanied Houston philanthropists Lester and Sue Smith and 200-plus breast cancer survivors, supporters and patients in a professionally choreographed flash mob dance to celebrate National Cancer Survivors Day while raising awareness about the disease.

Pink power ruled as participants wore specially branded T-shirts, wigs and glitzy disco hats and shook hot pink feathery boas and pom-pons to the music.The Smiths, two-time United States Grand Senior Latin Dance Champions, performed a choreographed disco number as Gaynor sang.

The impromptu rave also launched The Pink Well Challenge, a $1 million charity challenge that will award matching funds to up to 20 organizations supporting the fight against breast cancer.

"All of us go through tough spots in our life, whether illness, personal struggle or financial concerns," oilman and two-time cancer survivor Lester Smith said in an interview. "This 1978 song is all about never stopping and getting strength from God. As long as you keep going, you will survive."

"I lost my sister to breast cancer in 2000," Sue Lester said. "This is my way to celebrate her life and commemorate her struggle."

The Smith's personal connection to the disease prompted the aggressive initiative to provide funding to breast cancer organizations. Groups from across the nation that want to participate in the Pink Well Challenge can apply for a grant online by July 1. A panel of judges will select semi-finalists, which the Smiths will review and pick the finalists. The finalists' videos will be posted online at pinkwell.org, where the public can vote for their favorite video and where the videos will raise awareness about the organizations' missions.

Dena Peavler was one of the dance participants getting down and grooving with her family supporters, encompassing four generations.

"I am myself a cancer survivor and was thrilled to participate," she said. "We had two rehearsals, only finding out yesterday night that Gloria Gaynor herself would be present. Her presence was very meaningful to us."

"This is a realization that you are not alone in this battle," Kelli Underhill, flash mob dance participant and survivor, said. "It's much more empowering to celebrate survivorship than attending memorials."

Though the flash mob lasted four-and-a-half minutes, the post dance conversation indicated that the effect on the audience and the participants will be long-lasting.

See the video of the Galleria flash mob and Gloria Gaynor: