Katy Perry gets personal about her journey to pop megastar and the songs on her upcoming album, Teenage Dream, in a new Billboard magazine cover story.

And while much of the stuff about Perry's early years has been well-documented — pastor's daughter strikes out in Nashville, does the major-label shuffle in Los Angeles, finds improbable success with hit single about snogging girls (and liking it) — the behind-the-scenes details on Dream are sure to raise more than a few eyebrows.

Perry talks in-depth about a handful of songs on the album, including "Circle the Drain," which Billboard's Monica Herrera writes is "about [her] ex-boyfriend, Gym Class Heroes frontman Travie McCoy," and features the lyrics "You fall asleep during foreplay/ 'Cause the pills you take, I know your forte/ I'm not sticking around to watch you go down."

"It's kind of like my 'You Oughta Know,' Alanis Morissette moment," Perry says.

She also claims that making much of Dream was a battle of wills with her all-star team of producers (which included Max Martin and Dr. Luke), one that she was determined not to lose, no matter the cost.

"I'm in the studio fighting with them to change the melody, or I'm fighting for the best lyric at all times," she says. "I think we rewrote 'Teenage Dream' five times for 10 days straight. On the last day, I was so happy to finally get somewhere that we all agreed on."

And she doesn't exactly shy away from expressing her opinions about some of her pop contemporaries either, taking an (assumed) potshot at Miley Cyrus — "I'm not coming out trying to prove anything to anyone, like, 'Oh, I'm in assless chaps!' or 'I can't be tamed!' ... I've already been through that phase" — and expressing no regret over the now infamous "blasphemy" tweet aimed, in part, at Lady Gaga and her "Alejandro" video.

"[Spirituality] is just important to me," she says. "The details of the importance are still to be determined, I guess. ... It's one of those things that as the older you get and the farther you try to run away from your parents, you just turn right around and they are embedded into your DNA."