If it's a small shop, the license won't be a huge amount. Probably about £1500? That means he could even have a live band in if he wanted.  Now - if he only played local bands on the radio, whom he had permission from to play the music, he wouldn't need a license, as he has their permission to do so.  Although, if he didn't I doubt he would be caught, if he did, the fine is craaazzzyyyy.