Katy Perry is the latest artist to grace the cover of Billboard magazine, and in her interview with the popular music publication, she revealed her follow-up single to her massive hit and anthem of empowerment "Roar". She confused fans with her release of "Dark Horse" just over a week ago, featuring Three Six Mafia rapper Juicy J, but the mystical song is not the official second single off Prism, her upcoming third studio album. Instead, the pop singer is going with "Unconditionally", which has been described as a heavy-hitting power ballad. The lyrics have not been revealed as of yet, but with the title, fans are assuming that the lyrical content will have to do with her significant other, John Mayer. Perry co-wrote the song with Emeli Sande, who is known for her soaring piano anthems like "Next To Me" and "My Kind Of Love". Katy's third album Prism will be released on October 18th, 2013. She mentioned in her Billboard interview that the sound and lyrical theme of the record will be more organic and raw, compared to her previous sugary-sweet pop confection of an album, Teenage Dream, released back in 2010.