About 85 students at P.S. 161 were in the middle of a choreographed routine Tuesday to "Single Ladies," a song adapted from Beyonce's hit "Get Me Bodied."
The singer joined in wearing stiletto heels and a T-shirt emblazoned with "Let's Move."
Thirteen-year-old Aisha Collier gushed "she's so beautiful."
She told the New York Post she messed up a little when Beyonce first arrived but then got back into it and continued to dance and have fun.
The children were participating in a national simulcast of "Let's Move Flash Workout." It's part of first lady Michelle Obama's fitness campaign.