Over outstretched legs, five teen dancers bow like swans in George Balanchine’s masterpiece “Serenade.” He choreographed the ballet as a teaching tool for his students in 1934.

They raise their torsos, and the mood shifts. They see one another. “You look and your friend is smiling at you,” said Vanessa Linden, 17. “She is offering a hand.”

At the School of American Ballet, the brightest of students learn from the best, like Suki Schorer, who has staged “Serenade” for the school’s Workshop Performances multiple times.

This weekend, she does it again with a new generation. Both the school — the training ground of New York City Ballet — and “Serenade,” set to Tchaikovsky, are celebrating their 90th anniversaries.

Linked like a chain, the dancers rise to full pointe, winding their bodies in and out of a horizontal line before closing in on what Balanchine called, Schorer said, a baseball huddle.

“The audience can’t really see your face,” Linden said. “We whisper to each other things like, ‘OK, you’ve got this.’”

They wind and unwind again, their positions flowing and spiraling by the angles of their épaulement, or the placement of the shoulders.

“This section is very simple, but we’re all together,” Tuscany Bramwell, 18, said. “It gives us time alone on the stage to look at each other. We really take in the moment.”

“You learn to dance in it,” Schorer said of the ballet. “How to really project your whole body.”

“It’s really dancing together with your friends. It’s like a party. Women together going forward in life.”