This explains it:
http://www.independent.co.uk/news/world/americas/walmart-to-boost-staff-...
Music tastes vary wildly from person to person but few people can actively hate instrumental-only music such as that which comes under the categories of 'easy listening' or 'elevator music' or 'jazz music'.
No vocals, just instrumentals. Maybe limit the genres to jazz and classical to start out with.
The world has changed and nearly everyone has a cell phone or smart phone in their pockets now. We can store our own music on those devices and listen to them if we like. We don't need stores to play their loud/obnoxious/stupid music.
Doing this as a formal federal policy will greatly boost the economy of America, trust me :)