It’s enough to make a teenaged girl combust. Justin Bieber and Taylor Swift have worked on a song together. But is Taylor Swift just co-writing, or will she be singing along?

According to RollingStone, Bieber has announced that his upcoming album “Believe,” will feature a songwriting collaboration with¬†Swift¬†– but he makes no mention about whether Swift will lend some of her signature vocals. (You can only imagine she will for maximum selling power.)

Bieber talked about it on the U.K.’s Capital FM Radio, saying that the single will have a country sound, but the album itself will have a broad range.

“It doesn’t stay in a box … Everything is so different and that’s why I’m so happy with this album.”

Other “Believe” artists include Drake, Kanye West, Timbaland, Diplo and Usher. It comes out this summer.

Many believe Bieber’s next album will be a test of whether he can successfully crossover into an adult sound. Bieber’s first single of the album strayed from his usual pop style, and it’s expected that he’ll be pushing himself outside the bubblegum pop sound on most of the tracks.

For more music news, follow @BrianBalthazar on twitter!