For the last three days right here in New York, the best high school jazz ensembles in the country have been getting the kind of instruction they could only imagine - if it wasn't actually happening.
But it was the instructor himself who may have been benefitting most of all.
The competition is called "Essentially Ellington."
Strictly speaking, there's only one winner, but given who's watching, critiquing and teaching, everyone walks away with a prize.
Wynton Marsalis, an American treasure, is the lead mentor here.
"We're not going to say this is fantastic playing if it's not because we want you to become the best that you can be," he said.
For the kids asking him questions, it's like talking, hitting with Babe Ruth. Does he detect the nervousness and anxiousness in them?
"Maybe for some in the beginning, but many have done a lot to earn the right to be here. You know 2,700 bands this year are participating in this competition. This is the top 15."
For three days, Marsalis and other top jazz artists conduct intensive classes for the next generation as well as record one student composer's work. This year it's a piece by Jeric Rocamora, a high school senior from Roseville, California, who couldn't fly to New York because of a collapsed lung. But when you're a jazz musician and can spend three days with Wynton Marsalis, you hop a train.
"It's kind of weird hearing your music being played," Rocamora said.
Especially by this group?
Watching Marsalis with these kids, you wonder who was the getting the most out of the last few days.
"I'm still a kid," Marsalis said. "I mean I loved and learned so much from seeing how they play."
For him, it's a way to reconnect with a certain undiluted passion of youth.
"You know, you get older, you become jaded, it's hard to maintain your enthusiasm the way that you had it when you were young," he said. "Because you didn't know what you knew. So the challenge is, how can I be wise and get the wisdom of an older person and go through all of the bumps that life is going to give me but maintain that passionate intensity."
Does this let him tap back into that?
"Oh I tap into it and I love it," he said.
As for the next generation, Rocamora will be attending the Berklee College of Music in Boston this fall on a full scholarship.