Breanne Düren was only playing music on the side behind her studies at the U when she got the call.

A friend thought she would be perfect to sing on another friend's recording. She would have to drive down to Owatonna, Minn., to deliver her part, though. Oh, and the session would take place in a basement where the other singer lived with his parents.

"Yeah, I didn't really have any idea what I was getting into," Düren said, laughing at the understatement.

That's the story of how the Apple Valley native wound up singing on the biggest Minnesota album of the past half-decade, Owl City's "Ocean Eyes." After Owl City's Adam Young recruited her for his million-selling homemade album, she then joined his band and toured the world, playing everywhere from New York's Madison Square Garden to Japanese venues where fans went berserk.

As she recalled it, "We started touring in a van in October [2009]. By November, 'Fireflies' was blowing up and we moved into a bus, and it just kept spiraling."

Before returning to the cozy Owl City nest for a summer tour behind the follow-up album (due June 14), Düren is testing her own wings as a solo artist. She just released a five-song debut EP, "Sparks," and is back home from promotional appearances in New York and Los Angeles to perform an early, all-ages show Friday at 7th Street Entry.

Known to her large family and old Apple Valley High classmates as Breanne Durenberger -- her dad is a cousin of former U.S. Sen. Dave Durenberger -- the 23-year-old bright-eyed beauty said she never gave up the idea of being a singer/songwriter even as Owl City became a full-blown, full-time sidewoman gig. She also never gave up her college work. She went back and earned her cultural studies degree from the University of Minnesota this semester, thanks to some online classes and flexible courses.

"It's been a busy couple of years," she said cheerily over coffee two weeks ago. "With Owl City, though, most of the attention and workload falls on Adam, like interviews and promotional stuff. So there's a lot of free time for the rest of us when we're on tour."

She wrote many of her songs on the road, where she found a supportive fan in Young. "I'm addicted to everything Breanne creates, and I'm totally fascinated with the way her mind works in terms of hooky melodies, vocal harmonies and song orchestrations," the Owl City singer said via e-mail. "I devour her new music like a ravenous wolf and I get so caught up in them, I snap back into reality and remember it's Bre! She's like a sister to me."

One listen to "Sparks," and you can hear Düren's musical relationship to Owl City. It's full of light, wholesome, sweetly sung piano pop with a touch of electronic flavor. It's less synth-heavy than Young's songs, though, and has some of the perky warbliness of Young's pen pal Taylor Swift.

The music is alike, and so is the game plan. Düren shares Owl City's manager and started her trajectory with a similar, self-generated online buzz. Her first single, "Gold Mine," was a free "Discovery Download" on iTunes two weeks ago. That helped push her EP into the top 10 on iTunes' pop chart. She also featured prominently on the TeenVogue.com and AOL music sites. Meanwhile, the video for "Gold Mine" -- featuring the dance team from her old high school (of which she was a member) -- might be the most smiley, cute clip not involving a cat or baby on YouTube right now.

With DIY Web success comes interest from record companies, one of which will probably sign up Düren in time to issue a full-length debut next year. She plans to continue playing with Owl City for a long time, but she also knows how quickly things can change.

"I've been lucky and given a great opportunity thanks to Owl City," she said. "It'd be a shame if I didn't take advantage of it and really dedicate myself to this."