Oh, you've pressed all my buttons with this one. It's everywhere and always they say it's head office's decision. I once found myself at the end of a tiring day shopping for shoes for my son, standing on a chair in a shoe shop beating a loudspeaker that was blaring out rap with my hat and yelling "shut up you moron, shut up". I gathered a decent crowd until my son led me gibbering away.
The ultimate was in a charity shop recently where two elderly ladies behind the counter were discussing their various ailments (have you noticed how you can't go in to a charity shop without having to listen to some terrible tragic health story?) Behind them a radio blared out;
"Iwant teen-age kicks all through the night." Bizarre.
In Shrewsbury there is a shop that plays quiet strict tempo dance music from the fifties a la Victor Sylvester with a violin taking a sedate lead. I find I spend more time browsing their books than any other shop.
In Canada the final dagger to the heart was muzak in bookstores!!!!!