Taylor Swift Is The Brian Box Behind Calvin Haris Hit Song.

According a close friend of Taylor Swift, Taylor is said to be the creative brains behind Calvin Harris' monster hit "This is What You Came For," and their relationship fell apart because he disrespected her when the song was released ... It's really a fascinating story. We've learned an early fan rumor about the song is true, but to a deeper extent than anyone suspected.

It was gathered that during their relationship, Taylor wrote the song, and did a demo of the song into her iPhone. She sent it to Calvin, who showed he loved it. They both went into a studio and did a full demo with Taylor on vocals and Calvin doing the beat. They both knew the song would be a hit, but Taylor wrote it for Calvin and both agreed it was a bad idea to let the world know they collaborated as a couple ... it would overshadow the song. So Taylor, who kept the publishing rights, used the pseudonym, Nils Sjoberg on the credits. Fast forward to April 29th. Calvin released the song with Rihanna and it became an instant hit. It's been at #1 or #2 on the Dance/Electronic chart for 9 weeks, and is #5 on the Billboard 100. The problem in the relationship came the day the song was released. Calvin appeared on Ryan Seacrest's radio show and Ryan asked, "Will you do a collaboration with your girlfriend?" Calvin responded, "You know we haven't even spoken about it. I can't see it happening though."