It only took the first few notes of the Dalton Academy Warblers' a cappella crooning to capture the attention of "Glee" fans everywhere when they sang Katy Perry's "Teenage Dream" in November, with the single taking the No. 1 spot on the Billboard chart. The latest "Glee" compilation, "Glee: The Music Presents the Warblers" comes out in stores Tuesday.
Five months after the a cappella group's first appearance on the hit Fox show, every "Glee" fan knows the fictional Warblers, but many still may not know the real collegiate group behind their favorite school uniform-donned singers.
The college students who make up the Tufts University Beelzebubs voice the Warblers that back "Glee" series regular and Warblers lead vocalist Darren Criss. As the cast of "Glee" films and records in Los Angeles, the Beelzebubs record their parts in between classes, in a studio about a mile away from their Somerville, Mass. campus.
Video: The "Glee" Warblers perform "Bills, Bills, Bills"
The Beelzebubs boarded "Glee" after the show's producers called the group's business manager, Evan Powell, a junior at Tufts. Powell received the voicemail from the producers while in a class and listened to it as soon as he walked out of the classroom.
"Of course I quickly called them back, and it all sort of ballooned from there," Powell said.
The all-male a cappella group was familiar with the recording studio -- in its 45-year history, the group has recorded 27 albums -- and with television, having appeared on NBC's "The Sing-Off" in 2009, placing second. But recording the songs before performing them live was new to the group.
"You're really skipping a step," explained Ed Boyle, an alum who arranges for the Beelzebubs and has arranged all of the Warblers songs. "You don't have to concern yourself with 'Oh, is this the exact number of parts as I have number of singers?'"
With multiple tracking and over-dubbing, the 11-member group can sound bigger than they can when singing live. They're also free to take more risks with range. A high or low note that might have been a risk to aim for live is fair game for the singers when they can record multiple takes in the studio.
Several Beelzebubs members hadn't watched "Glee" before when they started singing for the show, but on Nov. 9, the group gathered around a big screen to watch their debut episode, "Never Been Kissed."
"I remember watching the iTunes Top 50 list [while the episode aired], just watching ['Teenage Dream'] climb. We were, 'Is it really gonna go up another one?' And 'No, that's it. That's the end.' And then suddenly it was at number one for like a week. It blew our minds," said Penn Rosen, the group's music director and a senior at Tufts.
The cover sold 55,000 downloads on the iTunes Store on its first day, breaking "Glee's" previously first-day sales record held by "Empire State of Mind."
Sales of the Beelzebubs' downloads also spiked. Since "Teenage Dream" was released, the group's average sales per month has quadrupled.
When on tour at other colleges and high schools, the Beelzebubs have found an enthusiasm in their audiences they hadn't witnessed before.
"I'd say at a lot of the gigs we go to, especially post-'Glee,' there are a lot of fans who kind of see us as celebrities," Powell said, "but definitely not at Tufts."
Rosen was quick to point out, "We all signed up for it because we wanted to have fun. It wasn't like we were chasing stardom. But I'd say when we travel, certainly it hits me, 'I'm a senior, and I'm going to graduate, and I'm never going to do anything [again] where people ask me for my autograph after a show.'"
Despite the sudden increase in exposure, the singers emphasize that they stay true to their longtime motto "Fun through song" -- and their lack of celebrity status on campus keeps them down-to-earth.
Getting a cappella into the mainstream has its pluses though, the groups' members acknowledge. "Choir kid" and "Glee club" can suddenly mean "cool."
"Before 'The Sing-Off,' before 'Glee,' before any of that stuff, we would be singing at high schools early Friday morning, and the kids would be texting on their phones, and they wouldn't be interested in hearing us, and we'd really have to fight to get their attention," said Beelzebubs president Eli Seidman, a senior at Tufts.
Things were different at an early February performance at Marblehead High School in Marblehead, Mass., when the Beelzebubs had to deliver the bad news that they wouldn't be performing "Teenage Dream" -- the song's soloist for the group had lost his voice.
One girl in the audience stood up and said, "Well, I know the words. I can sing it." Another girl leapt from her seat and said the same. Soon the whole audience was offering to sing the lead part.
A chorus of about 300 high school students belted out the lyrics as the Beelzebubs sang the background parts.
Seidman recalled, "The principal came up to me afterwards and said, 'We had been trying to get kids more interested in music for 10 years in this school. You did in one day what we have been trying to do for years and years now.'"
With what appears to be a wrap-up of the Warblers' storyline, the Beelzebubs know their time with "Glee" is probably coming to an end.
"As far as what happens next, we're as anxious to find out as you are," Powell said. "Last year after 'The Sing-Off' we thought, 'That must be it. It must be all downhill from here,' and then 'Glee' happened. So who knows?"
While the next phase in Beelzebub history is still a mystery for everyone, the future has plenty in store for the group: Following Tuesday's release of "Glee: The Music Presents the Warblers" is another "Glee" episode featuring the voices of the Beelzebubs. In the fall, the group will release its 28th album.
"Glee" returns Tuesday at 9 p.m. on Fox.