It sounds like the setup to a cheesy joke: A Jewish synagogue and a Catholic school team up to put on a music festival, and ’90s alt-rock group Gin Blossoms is the headliner.

Yet it’s very much happening, in the St. Louis Park nook where Beth El Synagogue and Benilde-St. Margaret’s School have stood across the street from each other for decades. The Common Sound Music Festival, a concert to be held Sunday and organized by the two religious institutions, is their latest and biggest undertaking yet.

It’s the sort of neighborly, interfaith collaboration that one doesn’t see very often, said Beth El Rabbi Avi Olitzky.

“We’re not aware of a Catholic school and synagogue relationship in the country that exists in the way this exists,” he said.

Beth El and Benilde-St. Margaret’s, a college prep school for grades 7 through 12, take full advantage of the relationship that comes with their proximity. Benilde students walk across the street to the synagogue to observe services, and Olitzky occasionally teaches at the school.

Olitzky and Adam Ehrmantraut, the president of the school, met at the rabbi’s office last week to talk about the festival. Olitzky said they had thought about hosting something like it for years, and the timing finally seemed right.

“We’re looking out at the world around us and the divisiveness and the conflict,” Olitzky said. “We can spend a moment and bring people together ... and say, ‘Here’s a great Sunday in Minnesota.’ ”

The festival will run from 4 to 9 p.m. Sunday at 5225 Barry Street W., St. Louis Park. Tickets are available at commonsoundfestival.com.

Themes of peace and unity surrounding the concert seemed to sprout out of the ground — literally. The festival will be held in the parking lot they share, a “common ground” that inevitably led to the festival’s name, Common Sound.

“The minute that we said it, we knew that was exactly what we were going for,” Olitzky said.

They brought in Sue McLean & Associates, the team behind the Basilica Block Party — another secular show held outside a religious institution — to help put it together. Gin Blossoms and The Big Wu, a memorable jam band birthed at St. Olaf College in Northfield, signed on to perform.

So did The Common Ground Company, a local bluegrass, Americana and folk band that reached out to organizers after they learned the name of the festival. Amanda and Berek Awend, married multi-instrumentalists, will perform with funk band The Champions.

There will be beer — and Israeli kosher wine with certified-kosher food trucks, too.

St. Louis Park has become somewhat of a hub for events drawing people from across the Twin Cities, Mayor Jake Spano said. City Pages magazine held its beer festival there this month, and the Twin Cities Film Festival will be screening in St. Louis Park this fall.

Common Sound, Spano said, is a natural extension of the relationship between both faith communities. (Another place of worship, Buddhist temple Wat Promwachirayan, opened across the highway last year.)

“It’s one of the things that makes me really proud of St. Louis Park,” he said. “Not only are [they] good neighbors to one another, but they are genuinely, honestly collaborative.”

For Amanda Awend, playing the festival will have a special meaning. She has worked at Beth El for 10 years, teaching at the preschool and leading youth religion programs. Her music combines roots and blues with Jewish prayers.

“As a musician, it’s obviously an honor,” Awend said. “To be on the stage and look out and see familiar faces that I’ve grown to know and love ... is kind of an amazing feeling.”

It won’t all be Jewish music, she stressed; a few covers will be thrown into the set list. Besides, as the title of the festival expresses, the melodies and rhythm are what bring everyone together.

“Music is a language of its own,” she said. “The themes are all just universal.”