Katie OâToole, a cast member of âJersey Boys,â walked onstage on a recent Saturday night and wowed the audience with a sultry rendition of Lesley Goreâs 1964 hit song âYou Donât Own Me.â
Just before Ms. OâToole left the stage, she turned to the band and shrieked over the roar of a standing ovation: âThank you, Rats, I love you guys!â
Ms. OâToole was giving a shout-out to the River Rats, a local rock band that invited her and five other Broadway performers from âJersey Boysâ and âMamma Miaâ to sing with them at Connollyâs, a Times Square pub, where a $20 cover fee paid for the kind of unique theater not advertised on any marquee.
Ms. OâToole and the other stage actors are more than friends with some of the River Rats â" they are colleagues. Five members of the band are also members of Local 1 of the International Alliance of Theatrical Stage Employees, the group that operates the sets and builds and breaks down the stages upon which Broadway stars perform.
âWe have a great relationship with the actors,â said Aarne Lofgren, 61, a stagehand, singer and string-bass player who helped start the River Rats 25 years ago.
âOver the years, many of the actors have been a part of our crowds and felt the love,â Mr. Lofgren said. âItâs the kind of love they are used to getting on Broadway.â
Once a year, as a way of saying thanks to their singing stagehands, many of the stars lend their musical talents to the River Rats â" a 10-member band from Edgewater, N.J. â" shortly after the curtains close on their shows.
The unusual tradition began eight years ago, the brainchild of Mr. Lofgren and his childhood buddy and fellow stagehand, John Thompson, 60, who is also a singer and washboard player with the band.
âOne night we just said, âHey, we work with a lot of talented people. Why not invite some of them to one of our gigs?ââ Mr. Thompson recalled. âThatâs how the whole thing started.â
Jennifer Noth, an understudy for the three leading women in âMamma Mia,â said that she was âthrilled to be a part of the River Ratsâ big night.â
âThey help us out all the time, and now weâre here to help them out,â Ms. Noth said shortly before going onstage with two fellow cast members, John Hemphill (vocals) and Daniel Cooney (acoustic guitar), to perform a song called âAngel From Montgomery.â
âItâs not like weâre throwing these guys a bone, because they are talented enough to stand on their own,â Ms. Noth said. âWe do it because we respect them as colleagues. We do eight shows a week and they are at every one of them. We know Aarne and these guys on a daily basis as our crew guys, but itâs great to see a different side of them. They really have an amazing gift.â
For the roughly 200 audience members who danced and sang along with the band, that Saturday night proved to be the ultimate Off Broadway event (Connollyâs is on 45th Street, between Broadway and Sixth Avenue).
âThis is an awesome show,â said Steve Lasser, a Wall Street broker who knows several of the River Rats from high school. âThereâs an awful lot of talent under the same roof.â
Between sets, Mr. Thompson talked a bit about the bandâs history.
âWe grew up in Edgewater, a blue-collar town on the banks of the Hudson River,â he said. âPeople from surrounding towns always called us River Rats, and thatâs how the band got its name. We play about four or five gigs a year, but this is our biggest night. We give our fans some Stones, some Springsteen and some original stuff, a little bit of everything.â
The River Rats were also joined onstage that Saturday night by the actors John Edwards and Russell Fischer, also of âJersey Boys.â
âThe house is so alive and the band is so skilled,â said Mr. Fischer, who plays the young Joe Pesci in âJersey Boys.â He sang Elton Johnâs âHonky Cat,â and Mr. Edwards energized the crowd immediately after with a rousing rendition of the Bill Withersâs 1971 hit âAinât No Sunshine.â
As Mr. Edwards performed with the River Rats, Roz Ryan, who plays the prison matron Mama Morton in âChicago,â sat in the audience at a table with several of her cast mates, all of them wearing huge grins.
âIâm enjoying this role reversal, watching our talented stagehands perform,â Ms. Ryan said. âItâs nice to be a part of the audience once in a while and watch someone else work.â