"Ahu" are stone platforms on which many moai sit. There are 313 known ahu and 125 of these carry moai. The biggest, Ahu Tongariki is 220 m (720 ft), and had the most (15) and tallest moai.
Imitation is being rewarded. They're learning that if you fit right in the mold, you get rewarded. Music is no longer a form of expression - it's a means to a lifestyle.