How crowded will Busch Gardens VA Williamsburg be on July 18?

I honestly dont know (if its because of the Commodores concert). I went to go see Kansas last weekend and the park wasnt that full. Honestly I thought it looked like a normal day at BG. I dont know how big of a crowd the Commodores are going to bring in, but atleast for Kansas it looked like a normal day. Still, its hard to say.