The Club is simple, really – the default dancing area when Worlds was active.
There isn’t much to say about The Club, except that it is one of the most normal places in the entire client. When you are a VIP (you get free two weeks of VIP when you sign up for Worlds) you can choose to have a 3D avatar. When you have a 3D avatar, you can make your character dance and perform other physical actions through a control panel. Obviously, The Club is one of the placeswhere this was utilized the most.
At least… it was.