There are Pokemon Centers in Washington around Seattle, but they're just vending machines with video screens that mainly play anime episodes in mall hallways really. The one in the Alderwood Mall in Lynnwood used to have two kiosks and shelves and people manning them (before it closed), but it still was in the mall's hallway. So while I can't say anything about the Japanese Centers, take it from the guy who's been there: the American Centers play no music except for whatever is playing in the anime episodes.
Creator of Jay's Journey (see quote!) "It's not ten years old! Therefore, it sucks!" - Nostalgia whores everywhere