Most of the time, when pop stars collaborate, you imagine that it's a simple case of 'Have your people talk to my people, get in the studio, done'.
Indeed, that might have been how Calvin Harris has worked in the past - but when you're trying to pin down a star as busy as Rihanna to provide vocals on your track, it's quite another story.
Harris has revealed the lengths that he went to to get Rihanna on 'This is What You Came For' earlier this year, when she was on tour.
He told Zane Lowe on his Beats 1 radio show: "In the end she recorded the vocals in New York. She was gonna do it in LA. She didn't, she couldn't. She had to finish her album.So it got pushed back a couple months and then there was a day in New York, or like some hours in New York that she had free because she was on tour at the time as well.
"I said, 'Well OK we didn't get the vocal last time, I'm gonna fly over to New York and just make sure that I get it because I really want it today. 'This is the only day she has on tour, if it's not today it's another two months, so can I come over?'
"So I checked into the Mercer and I waited for her engineer to call me. Her engineer didn't call me and then I was texting him and I was like, 'Is she there yet?' she wasn't there yet. In the end it was 4am I fell asleep. I woke up at like 8 to three texts from him and he was like, 'We got it. It's great, let me get everything together for you. And you can come pick it up tomorrow'.
He added that the engineer finished working on the track at 2pm, and his flight was at 4pm. "We left the hotel, I had this brown bag with a hard drive in it. We drove to the studio, we heard the vocal once. I'm like 'that's great', they put it on the hard drive, I put it in my bag, we drive around the corner to the helipad, we take off in the helicopter to the airport and I have this priceless vocal in my brown bag.
"Get on the plane, I sat it there opposite me in the seat, I looked at it and I was just like that was like a bank heist. That felt incredible, knowing that I had the most important vocals that I've ever got and it felt amazing. I would've waited six months for it."
It seems that Harris's efforts paid off, as the track turned out to be one of his biggest hits to date...
