Belt out the holiday classics at the Jingle Bell Jamboree on Saturday

Belt out the holiday classics at the Jingle Bell Jamboree on Saturday

“This isn’t the kind of concert where we expect the audience to sit and politely clap.”

So warns Ethan Schlesser. For his annual Jingle Bell Jamboree, the PS 97 choir teacher pulls together some of the borough’s best performers to not only entertain you, but get you to your feet and belting out holiday classics and singalongs.

On Dec. 18, the Old First Reformed Church in Park Slope once again hosts the holiday show, a variety act now in its 10th year that will feature the Brooklyn Technical HS Choir, the “Old First” Family String Band, the St. Joseph’s HS Step team, the PS 97 Show Choir, and such regulars as the Brooklyn Community Chorus.

“The first year we did it, we had a singalong that was very low key. It was almost like you were at a friend’s house having a holiday gathering,” said Schlesser, who, in addition to manning the piano, will also perform a vaudeville-style opening number with the church’s pastor, Rev. Daniel Meeter. “For me, it’s important to keep that spirit. The audience is involved throughout the concert.”

That couldn’t be more true than in the big finale — a performance of “The 12 Days of Christmas,” where unsuspecting members of the audience are picked to act out the various “gifts.”

“If a group does poorly, we stop the singalong, point at them and say you have to do better again,” said Schlesser. “It’s pandemonium.”

Jingle Bell Jamboree at the Old First Reformed Church [Seventh Avenue at Carroll Street in Park Slope, (718) 638-8300], Dec. 18 at 7 pm. Suggested donation of $10, $5 for children.