Stealth Guest Billy Joel Turns Fanboy at Kindergarten Tribute

You can take the boy out of New York, but you can't take the New York out of the boy.

Billy Joel made an undercover appearance at the Deasy Elementary School spring concert in Glen Cove, New York, on Wednesday, to take in the kindergarten performance of "The River of Dreams: A Billy Joel Tribute."

The Piano Man was invited to the concert in his native Long Island community by the school's principal and a teacher, who had selected 15 of Joel's songs for a group of 5- to 7-year-olds to sing. Since the Bronx-born singer still lives locally they hoped he'd join them. Alas, he never responded to their email request.

"Five minutes before the concert was set to begin, he walked in the building with other parents and invited guests and took a seat and really blended into the crowd," Maria Rianna, Glen Cove School District's superintendent told Yahoo. "The principal came over and asked him if he would like to move to the front of the auditorium. He said he didn't want to make the kids or teacher nervous, so he would sit toward the back."

Joel remained in the rear of the auditorium and "was clapping and speaking to some of the parents that were around him" before he made an early exit.

The school district's television class captured video of the star clapping wildly after the children performed "Uptown Girl."

"He enjoyed the good portion of the concert before he had to leave. We were really happy to support the kids in the manner in which he did," Rianna continued.

This isn't the first time the "Just the Way You Are" crooner has made a fan's day.

In January 2013, Joel invited Vanderbilt University student Michael Pollack up on stage to perform "New York State of Mind." Pollack, who asked Joel for permission to jam together during an event at the university, played piano while Joel belted out the ballad.

Strangers aren't the only ones to go gaga over warbling with the Rock and Roll Hall of Famer. Jimmy Fallon could barely contain himself last week during a doo-wop duet with Joel on "The Lion Sleeps Tonight" on an episode of "The Tonight Show."