Swift is said to have used the pseudonym of Nils Sjoberg on the credits of the song. Calvin Harris has also confirmed the news via Twitter.
According to TMZ, Swift wrote the song at a piano and made a demo on her iPhone, which she then sent to Harris, who reportedly “loved it.” They felt it would do well but were afraid that having both their names on it would distract from the music, so Swift agreed to use the pseudonym, retaining the publishing rights to the track.
Harris has since taken to Twitter, writing: “And she sings on a little bit of it too Amazing lyric writer and she smashed it as usual,” before adding, “I wrote the music, produced the song, arranged it and cut the vocals though. And initially she wanted it kept secret, hence the pseudonym”
Harris then appeared on Ryan Seacrest’s radio show on the day of the release, with the host asking if he would collaborate with Swift. He replied: “You know we haven’t even spoken about it. I can’t see it happening though” – a comment which Swift found “hurtful” according TMZ.
Harris then continued to tweet: “Hurtful to me at this point that her and her team would go so far out of their way to try and make ME look bad at this stage though,” before adding, “I figure if you’re happy in your new relationship you should focus on that instead of trying to tear your ex bf down for something to do” which may be pointing towards her relationship with Bond hopeful Tom Hiddleston.
Harris continued: “I know you’re off tour and you need someone new to try and bury like Katy ETC but I’m not that guy, sorry. I won’t allow it,” before finishing, “Please focus on the positive aspects of YOUR life because you’ve earned a great one. God bless everyone have a beautiful day”