She always has to keep them guessing. Normally known for writing songs that keep her fans searching for hints as to which celebrity ex-boyfriend inspired them, Taylor Swift is apparently taking a slightly different angle on her upcoming album 1989.

The singer appears as Rolling Stone’s September cover girl. Swift, 24, spends much of the article talking about how her new life in NYC includes a large contingent of female friends, but warns that she values loyalty as much with them as with her boyfriends. She tells the reporter that an angry song on the new album, called Bad Blood, is about another female singer who tried to undercut Swift’s career. In 2013, Swift explains, “she did something so horrible. I was like, ‘oh, we’re straight up enemies.” And it wasn’t even about a guy! It had to do with business. She basically tried to sabotage an entire arena tour. She tried to hire a bunch of people out from under me.”

The internet has run wild with speculation on who Swift is referring to, and sites such as the Huffington Post posit that the female artist in question is Katy Perry, who convinced three of Swift’s tour dancers to leave her mid-tour and join Perry’s own tour last year. Perry has not explicitly commented on the rumors but seemed to refer to them with a clever Mean Girls reference on Tuesday, tweeting, “Watch out for Regina George in sheep’s clothing….”

1989 arrives in October.