Music, they say, is the food of love and, we suppose, of sex... and also of shopping.

More thought goes into choosing the tracks you hear at the supermarket than you might think. According to retail experts, music with a slow beat gets people buying more than music with a fast beat.

Of course, in many places the music is there primarily for the pleasure of the clients - in clothing stores, for example, or often in bars and restaurants. But it’s not just retailers and their clients who are interested in the music that's played. It also concerns composers, lyricists, performers and producers, all of who get money when their music is in the air, even if it comes off the radio.

The composers and lyricists are looked after by SACEM, the French performing rights agency. In 2009, they picked up €124 million in payments for music heard in public places, much of it in shops. The performers and producers rely on la Spré, which is concerned to guarantee its members "fair compensation" (rémunération équitable) for their efforts. The payments it demands - based on the records of SACEM and related in each case to what’s asked for by that organisation - doubled last year and on top of that, for every employee beyond two there is now an annual supplement of €47. How are those affected reacting to this?

Answered one hair salon owner, "My yearly fee of €35 jumped to €60 in 2010 and this year it’s supposed to go up to €90 - that’s the price of three haircuts. I’d be better to turn off the music and lose a few clients."