Debbie Allen was not there to play games.

The three-time Emmy-winning choreographer, actor, and executive producer of Grey's Anatomy made that very clear Tuesday morning to about 40 students at the String Theory School, a performing arts charter school at 16th and Vine Streets.

Allen was there to lead a 90-minute master class with high school students as a part of the Mann Center's 2017 artist-in-residency program, and she went right into the dance drills: deep dips, then plies, then high kicks that ended in a graceful twirl.

"I'm trying to give them what someone gave me," the 67-year-old dancer said.

She meant discipline, not calluses.

"The discipline that you get from participating in art," Allen said, "whatever your art is, there's such value."

Halfway through the class, the students were visibly tired. Not Allen. She got in their faces, pushing them to kick higher, to make their movements larger. She clapped her hands to a syncopated rhythm.  Her energy was contagious.

Before long, she was leading the group in a routine to Bruno Mars' "Uptown Funk."  When Allen stepped into the "nae nae" and rolled her hips, the students went wild.

The class ended in a fun freestyle, where dancers showcased their individual talents. After that were selfies, laughter, and a lot of splits.

For student Siani David, 18, who mostly dances hip-hop, Allen's class was an inspiration to expand her horizons.

"I learned how to loosen myself up," she said. "And she opened me up to modern dance."

Then the String Theory students’ superstar dance instructor (her Debbie Allen Dance Academy in L.A. is in its 17th year) and sister of actress, singer, and stage director Phylicia Rashad was on her way to the next gig. Allen was scheduled immediately to teach another 90-minute master class, this one at Philadelphia’s High School for Creative and Performing Arts. She was also scheduled to hit both schools again Wednesday, in reverse order.

"When you hang with the young ones," Allen said with a laugh,  "you stay young."