Every day, youngsters at Elwyn Institute's T-camp, or therapeutic camp, pound away on plastic drums.
They beat out rhythms, and make up funny stories to go along with them.
Joshua tells his fellow campers, "The slime gets into the water, and makes little aliens."
The drum sessions also give the campers - all on the autism spectrum - lifetime skills that may come easier to other children.
They learn to express themselves -
And they become aware of others around them, and how to work together as a group.
Drum leader Julius Rivera says what seem like silly phrases are serious language lessons.
"A lot of what we do focuses on language," he says.
"The repetition really helps them a lot."
Rivera says every little bit of progress counts.
"They're having fun, but they're productive. They open up a little bit more, which is awesome. They're continually surprising me," says Rivera.
The campers will put on a show for their families later this month, but Gabby Desnouee, Elwyn's director of autism services, says the daily participation is the big accomplishment.
"Children with autism will often respond to music, while they may not respond to other interventions," says Desnouee.
She says the drumming program, just 3 years old, gets more & more popular with each year. This year, about 55 students are taking part.