Mark Ronson made 17 different versions of 'Uptown Funk'.
Mark Ronson
The chart-topping producer released the hit single with Bruno Mars in 2014 and Mark's revealed he has various versions of the tune featuring "different basslines, different hooks, different programming, different chops, different everything".
He reflected: "The song wouldn't have been as good if it wasn't for Bruno. I think people think I made 'Uptown Funk' and sent it to Bruno to do the vocal.
"But that song is very much his creation. I remember spending three days in Memphis slaving over that song and thinking that we finally had it. I then got a call from him two days later saying, 'No, it's not it.' And I knew deep down it wasn't it either."
The 40-year-old star also admitted his most recent album, 'Uptown Special', marked a landmark moment in his career.
He told the Sunday Telegraph newspaper: "It took me so long to figure out something really obvious.
"That if I wanted to make another album and I want anyone to care then I'd better do the thing that I'm really good at, or the thing that I understand. And that's black American music from the 70s and 80s."
Tagged in Mark Ronson Bruno Mars