Calvin Harris doesn't do remixes for money.
The 'Bounce' DJ and producer has cut tracks with Florence Welch, Dizzee Rascal, Tinie Tempah and Kelis, and says all his collaborations come about as a result of favours and swaps.
He told The Guardian newspaper: "I can't remember the last time I did a remix for actual money. For me I try and get a good swap.
I remixed 'Spectrum' for Florence in exchange for a vocal part from her.
"It's old-school but it worked out beautifully.
"Every remix I've done in the last couple of years has been a swap for some other musical thing. As for money, that's not even a factor - you could not buy me to remix one of your records. But if it's something I wanted to do, I honestly couldn't care less if I got £5 or £50,000."
Calvin, 28, also prefers to record with female singers, as their voices work better on dance tracks.
He added: "They're always at the perfect frequency to play in a club. A good, soaring, high-mid female vocal bounces off the walls nicely, and it doesn't interfere with the bass or drumbeat. It's basic science. A man's voice is likely to interfere with the bassline which is why you don't hear many classic dance tracks with a male lead."
Calvin's latest album, '18 Months' is out now.