Mt. Joy, the band certified ‘fantastic’ by Jason Kelce, is playing a hometown show at the Mann

Mount Joy is the highest point of elevation in Valley Forge National Historical Park. But it’s not a real mountain, rising just 426 feet above sea level.

But Mt. Joy, the band led by Matt Quinn and Sam Cooper that takes its name from that wooded hill in Montgomery County? Their rise in the pop music world has been sky high.

The ascent began immediately after Quinn and Cooper, who first played music together while at Conestoga High School in Tredyffrin Township two decades ago, formed a band years later while they both lived in Los Angeles in 2016.

Their first single, the Jerry Garcia-name-dropping “Astrovan,” was an immediate Spotify success. The band sold out a show at Johnny Brenda’s in Fishtown the next year and have steadily climbed the music venue ladder over three albums, the most recent being 2022′s Orange Blood.

That’s meant steadily moving up the Philadelphia venue chain. Last summer, they played the Skyline Stage at the Mann Center, and now on Friday they’re set for their biggest hometown show at the Mann Center’s 13,000-capacity TD Pavilion. They’ll play two sets with no opening act.

Mt. Joy has also broken big nationally, performing at fabled venues like the Hollywood Bowl and Red Rocks this summer. The five-piece band that includes keyboard player Jackie Miclau, bassist Thomas Hughes, and drummer Sotiris Eliopoulus has a date at Madison Square Garden on Sept. 28.

And the band is also getting cozy under the mistletoe with Jason Kelce. On A Philly Special Christmas Party, due Nov. 29, Mt. Joy teams with the ubiquitous retired Eagle for a version of their signature song, recast as “Santa Drives An Astro Van.”

“They’re just a fantastic band,” said Kelce, who first saw Mt. Joy at a Philly Music Fest gig at Ardmore Music Hall in 2022. Last year, he joined them at the Skyline Stage along with his ex-Eagle pal Connor Barwin and sang along to “Silver Lining,” and the Eagles’ fight song.

At the Mann this week, Mt. Joy is partnering with Kelce’s (Be) Philly and Barwin’s Make The World Better foundation, and is teaming up with Sharing Excess for a food drive, while also working with voter registration organization HeadCount.

“They’ve blown up, and they’re playing these massive venues now,” said Kelce. “It’s been really really cool to see a band of Philly kids now be on the stage they are.”

Quinn, 34, is a guitarist and the band’s principal songwriter and vocalist, and Cooper, 35, plays lead guitar. They’re lifelong Philly sports fans whose song, “Cardinal,” on their self-titled 2017 album is in part an ode to Eagles tailgating in the shadow of I-95.

Speaking via Zoom from a backstage green room before a show this week in Charleston, S.C., they sounded thrilled to be collaborating “with a bunch of football players crushing it on Christmas songs,” as Quinn puts it.

“I just feel really fortunate to be able to make a record, not just with Jason but also [producer] Charlie Hall and everyone in the Philly Specials universe,” said Quinn, who came up with the idea of retelling “Astrovan” with jingle bells. “It was really fun to be a part of.”

Mt. Joy’s long road from Chester County began at Conestoga, where Cooper was two grades ahead of Quinn. His younger brother told him about a kid who was writing songs worth hearing.

Cooper was impressed by what Quinn said were his “angsty teenager emo singer-songwriter” tunes. They bonded over the Dead and Dave Matthews, My Morning Jacket, and Damien Rice. Calling themselves Gatsby, they gigged at coffeehouses like Milkboy in Ardmore, and Burlap and Bean in Media.

The partnership faded as they headed to college — Quinn at Northeastern in Boston, Cooper at NYU. But they never lost touch.

In the mid-2010s, Quinn moved to California with a girlfriend and started taking law school night classes, and Cooper headed to Los Angeles after graduating from Temple Law School.

“Just because we didn’t know anybody else,” Cooper said, they started playing together again. Soon, they had “Astrovan,” a catchy Quinn-penned folk-pop song featuring a hippie Jesus tuned to the Dead in his Chevy van.

The duo recorded that song and a handful of others on the cheap, along with Hughes on bass and producer Caleb Nelson. After completing five songs, Nelson asked, “What’s this called?”

Cooper grew up in Valley Forge, Quinn in Devon. Mt. Misery, also in Valley Forge, seemed too gloomy. So Mt. Joy, the wooded trail with a buoyant moniker whose vibe matches the band’s music became the name.

“Astrovan” made an immediate Spotify splash. “I recall being in the library and refreshing the numbers and just being like ‘Holy Crap, we’ve really got something here’ And then dropping out like 10 days after that,” said Quinn.

Cooper had moved back to Philly and was working at a Center City law firm while “Astrovan” was taking off. “I just remember staring at my laptop watching the Spotify numbers go up and thinking, ‘What am I doing?’ ”

They left their law careers, and Mt. Joy has been on the road ever since. Even during the pandemic, the band was far more active than most. They played a series of drive-in shows — including one in Citizens Bank Park’s parking lot in August of 2020 — while the world was mostly shut down.

“It wasn’t pretty,” said Quinn. “People had to tune in on a radio station in their car. But they just wanted to get out of their house and see their friends and experience live music in some way, shape, or form.”

“I think we’ve become a uniquely great live band, and we’ve had the time and space to get better over the years. But the way we grew our audience when the industry was shrinking helped us reposition ourselves when everybody went back on the road.”

Today, Mt. Joy is bicoastal. Cooper lives in Laurel Canyon and the other band members are also in LA, but Quinn moved back to Philly in 2020. He lives in Kensington with his wife, Ingrid, who moved to the U.S. from Brazil at 15 — a journey that partly inspired the band’s road-diary new single “Highway Queen,” with Maren Morris.

The band is midway through a new album slated for 2025 that’s likely to include an untitled new song cowritten with Nathaniel Rateliff, who joined the band at Red Rocks last month.

“As a band, our beginning was a little strange,” said Quinn, “because we were guys from the Philly area who got their start in Los Angeles.” But since he moved back, Mt. Joy has aimed to strengthen its hometown ties, starting with the 2022 Philly Music Fest shows that connected them with Kelce.

Playing a hometown gig at the Mann “is beyond anything I ever imagined,” said Quinn. “I grew up going to concerts there. I remember going see Damien Rice in high school and being mesmerized. More recently, I saw James Taylor.

“To have our music in a venue that hosts artists like that, with such an amazing history, only a few miles from my house … My friends and family will all be there. Cliché or not, it really is a dream come true.”

Mt. Joy at the TD Pavilion at the Mann Center, 5201 Parkside Ave. at 8 p.m. Sept. 20. manncenter.org.