It's all in the mix: the best fashion show music

"When you play something for a designer and you see their eyes light up, that's when you know it's going to work," says Rene Arsenault, the maestro behind Tom Ford's show music.

If you thought compiling the soundtrack for a top fashion show simply involves hooking up the designer in question's iPod to the venue's speakers and hitting 'play' you'd be seriously underestimating the process. According to Frédéric Sanchez, responsible for last month's Prada show pumping out Britney Spears's Work Bitch , "the whole process, which often ends hours, if not minutes, before the show - takes about 40 hours in total," he told Business of Fashion.

No surprise then, that the relationship between a top producer and a designer is an exceptionally close one, on par, perhaps with that of a woman and her hairdresser. Michel Gaubert, who made the inspired choice of Jay-Z's Picasso Baby for Karl Lagerfeld's art-themed show, has been working with the Chanel creative director for some 20 years and similarly, Simone Rocha turned to her brother, Max, to curate her own playlist which included the brilliant Atmosphere by Joy Division.

Gaubert was also charged with the music for Céline - a specially produced mix of Soul II Soul's Back to Life to match Philo's street style inflected collection. And when it came to the Sister by Sibling show, the designers turned to French producer Jerry Bouthier. They opened to You've Got Good Taste by The Cramps: "We though oh how brilliant to open a show with the line 'this one is dedicated to all you Gucci bag carriers out there,'" laughed Cozette McCreery.

As for the question 'what makes a playlist great?' the answer isn't cut and dried. "Anyone can play the newest sound in a show," continued Arsenault, but, "a good fashion soundtrack must feel unique." It's all in the mix - a mercurial one combining zeitgeist with taste and a certain je ne sais quoi…