I believe the music is there to mess up your judgment, so you don't have the spare brain-power to compare value-for-money, and end up just buying the stuff on the nearest shelf, which is always the dearest.
I always walk around noisy stores ( if I simply have to shop there in the first place) with my fingers in my ears. Bonus if it stops the people demonstrating new products from buttonholing me.
But what really gets up my nose is the pointless rattling music on television programmes like Real Cops - if a law-breaking scenario isn't exciting in its own right, stupid raucous music isn't going to make it exciting. In fact, it's going to make me turn off.