Darren Criss is giving himself a headache. The "Glee" star has already spent 45 minutes running through his entire adult life over the phone in painstaking detail -- "I'm getting ready to write my memoir," he jokes -- and cutting it short is hard. When he arrives on set for makeup, Criss, 24, tries to multitask. "I'm gonna be really L.A. I'm gonna put the Bluetooth in my ear," he says remorsefully. Within 15 seconds, though, he's abandoned that idea and escaped his glam squad in order to keep talking without interruption, marveling at his luck and plotting his next act out loud.

One might say "Glee" is Act 2 -- the first is set at the University of Michigan, where Criss, a mop-topped San Francisco kid fond of covering Alan Menken-era Disney songs, staged the very viral "A Very Potter Musical" with friends, started a musical theater production company (StarKid), co-produced the first student musical to chart on Billboard's Top Cast Albums ("Me and My Dick," in March 2010) and released an EP of singer/songwriter tunes ("Human"). In November 2010, of course, he landed the role of curious, confident and openly gay Blaine Anderson on "Glee" in his third audition for the show.

Video: "Glee" Warblers perform Katy Perry's Teenage Dream

It's not like "Glee" was hurting for success before Criss arrived. But with his dark curls and a rich tenor that envelops pop hooks not unlike a bearhug from your No. 1 high school crush, Criss has made an instant impact on the show's music sales. "Teenage Dream," the Katy Perry hit performed by Criss and his fellow Warblers (played by the Tufts University Beelzebubs), became the fastest-selling digital track in "Glee" history, and arguably ushered in the trend of more current pop hits being reworked by the cast.

'Glee' Video Exclusive: Darren Criss on Covering

Beyonce, the Beatles for Warblers Album

As Fox and Columbia Records gear up to release an all-Warblers "Glee" soundtrack (scheduled for April 19), the question of whether Criss will ultimately sign a solo deal -- so far, only Matthew Morrison has inked one, with Mercury Records -- hovers, and Columbia/Epic chairman Rob Stringer is happy to entertain it.

"We have huge belief in Darren Criss -- huge belief," Stringer says. "And when the time is right, we'll do good work together on his solo record." When, however, is still up for speculation. "Part of the joy of the show is in the ensemble-ness of it, so we're taking it very slowly and very carefully," Stringer says. "I don't think 'Glee' is going away, so we've got time."

Criss talked to Billboard about his beginnings, running StarKid and playing arenas on the "Glee" tour. 

Billboard: How did you first get into musical theater? 

Darren Criss: For me, it was Disney. I remember seeing people's reaction to "Aladdin" and thinking, "Oh, man, I want to be a genie when I grow up!" Robin Williams is a pretty big character in San Francisco. I was like, "I want to do whatever that guy does. What does he do, Mom? He's an actor? OK, I want to do that." I was all over the map, musically. I had all the "Les [Miserables]" and Andrew Lloyd Webber records, and I was a kid growing up in the '90s, so [I listened to] whatever pop was out at the time.

When did you first start to perform? 

I was writing a lot of music in high school, and I enjoyed playing my own stuff but only if people asked. I figured at an open mic, I could either play a song about my own personal struggle with x-y-z, or I could play a Disney song, like "Part of Your World." If you can tap into someone's nostalgia, you've got it. People get into it. It's the gateway drug into "What else does this guy play?" That was my parlor trick.

After college I continued to play at coffee shops in L.A. because I had this huge backlog of music. I'd play for like four hours straight, and I'd never play the same song twice. I'd do it for like 50 bucks and it just made me happy. What's crazy is everything I'm doing now on "Glee" is just an extension of what I've been doing my whole life. If they hadn't given me "Teenage Dream," I would have been playing it in a cafe somewhere.

Video: Darren Criss in "A Very Potter Musical"

Rewinding to college for a second, what was your reaction when "A Very Potter Musical" took off? 

The day we put it on YouTube was the day my life turned completely upside down. There was a completely unanticipated, bizarre reaction where we fell ass-backward into this phenomenon of the Harry Potter fan community. Within a week we had like the No. 1 viewed video in 50 countries. We thought, "We have an audience -- we should start a production company." We put my "Human" EP out at the same time as the StarKid albums ["Me and My Dick" and "A Very StarKid Album"], so we had three albums charting in a year. I think the record labels were like, "What? How is this happening? Who are these kids?" It's a testament to what's possible in our generation. Case in point, Rebecca Black.

Does your "Glee" contract give you the flexibility to continue working with StarKid? 

I was pleasantly surprised with how accommodating they all were. ["Glee" co-creator] Ryan Murphy has been extremely supportive. He knows about StarKid . . . and he's come to my shows. And there's a certain amount of credibility that they lend to it, which I'm appreciative of. So while I continue to work on our next musical, "Starship," I'm not singing on that record; it's just me as a writer.

NEXT: Darren Criss Talks "Glee" Tour, Marshmallow Castles