For more than a decade, Straight No Chaser has taken what started out as a collegiate hobby and turned it into a career that has taken them around the world.

The male acapella sensation bring its “The Open Bar Tour,” to State Theatre Center for the Arts in Easton for two shows, 3 and 7 p.m. Dec. 22. The tour is in support of the group’s seventh album, the retrospective “One Shot.”

Allentown native Jerome Collins says the concept album takes listeners through the story of Straight No Chaser who all met in show choir at Indiana University in the 1980s. He says the new album includes several songs from those early days.

Collins says a cover of the Def Jam hit “This is How We Do It” and a cover of Toto’s hit “Africa” were hits on campus but it was a goofy version of “12 Days of Christmas” that would become their breakthrough song.

After college, the members all went their own separate ways, but in 1998, the Indiana University choir members reunited for a 10-year reunion. As part of the festivities, they made a video of themselves singing “The 12 Days of Christmas.”

“It was an inside joke,” Collins says. “We never thought anything would come from it.”

Eight years later, original member Randy Stine posted the video to YouTube and to everyone’s shock, it went viral, becoming the No. 1-viewed video in 2007, receiving more than 7 million views that December and now having nearly 23 million views.

Atlantic Records called and before long, the 10 choir members were in the studio recording the group’s debut album, “Holiday Spirits,” which went gold and became the No. 1-selling album on the iTunes and Amazon.com charts in 2008, followed in the next year by “Christmas Cheers.”

“It was scary to jump into because we were giving up life as we knew it,” Stine says. “I envisioned it as a boat leaving the pier. Either you’re going to jump on and make the boat or you’re not. And I thought, ‘Even if the boat sinks and I have to swim back to shore, so be it.’”

Straight No Chaser went on to sell out concert venues across the United States and release six more top-selling albums and four EPs. Along the way, Straight No Chaser has sold more than 1.6 million albums in the U.S. and amassed more than 100 million YouTube views thanks to tightly-arranged songs, impeccable vocal harmonies, and a healthy sense of humor.

“One Shot” features 16 songs and 10 entertaining conversational interludes in which the members of Straight No Chaser trace their unlikely rise to fame. The songs reflect that sense of now or never, starting with opener and first single “Motownphilly-This Is How We Do It,” an energetic mash-up of Boyz II Men and Montell Jordan.

“Motownphilly,” with its lyrics about chasing improbable success, captured the way the singers felt as undergrads,” says Stine. “The lyrics from the Boyz II Men song fit our experience: We dreamed about this and now we are doing it, performing all over the world.”

The group’s lineup also features Forks Township native Walter Chase, as well as Seggie Isho, Michael Luginbill, Charlie Mechling, Steve Morgan and David Roberts.

All of the members take part in choosing songs, which mirror the singers’ music tastes, ranging from R&B and old-school funk to folk and classic rock.

In addition to “Motownphilly-This Is How We Do It,” the group performs Ricky Martin’s “Livin’ La Vida Loca,” Fleetwood Mac’s “Go Your Own Way,” James Brown’s “Papa’s Got a Brand New Bag” and Percy Sledge’s “When a Man Loves a Woman.

There’s also a take on Loverboy’s “Working for the Weekend,” Johnny Cash’s version of “I’ve Been Everywhere” and a richly harmonized version of Simon & Garfunkel’s “Homeward Bound.”

“We all rallied around that song because it really spoke to life on tour,” Stine says of “Homeward Bound.”

“We are loving what we’re doing, but there’s always a bit of you that’s missing home. Especially with all of us being parents now, it’s that much tougher when you leave.”

Straight No Chaser’s success has allowed them to collaborate with luminaries like Paul McCartney, Stevie Wonder, Elton John and Dolly Parton and landed them on national TV on “Today” and “Late Night with Jimmy Fallon.” They consistently rank among Pollstar’s top 100 touring acts in North America.

“We literally have to pinch ourselves every day that this actually happened,” Collins says. “We’re still in the game and we’re still a successful act. We started this just for fun and now we’re doing it as a career.”

Last year saw the release of a 10th Anniversary Edition of “Holiday Spirits” featuring two brand-new bonus tracks, “That’s Why We Celebrate” and “The 12 Days Of Christmas: 2018 Remix (Live).”

Collins and Chase look forward to playing for a hometown audience.

“There is nothing like coming home,” Collins says. “It’s exhilarating to see people laughing and smiling at our concerts. I want to put my best foot forward in front of the home audience.”

Collins says the group’s members always like to meet fans and take photos after every show.

“We like to get personal since our success was so grassroots,” he says.

Tickets: State Theatre Center for the Arts box office, 453 Northampton St., Easton; statetheatre.org; 1-800-999-7828; 610-252-3132