We just got back from a couple night stay at the W Lakeshore in Chicago. My four year old loved the W and it's 'cool music'. He danced his tail off every chance he got. Waiting in the lobby, waiting for the elevators, in the hallways, etc... Even the other guests who happened to see him dancing thought it was a hoot, although he did save his best moves for inside the elevator.
My four year old highly recommends the W.
When we stayed at a different hotel chain after leaving the W, he wondered why the other hotel didn't have cool music too?!?
Maybe it does come down to age.