Flying Sculptures In The Park

1- The flying sculpture must be heavier than air and hover 4 feet off the ground under its own power for at least 30 minutes without refuling.

2- It must be an original sculpture.

Not aircraft in the typical sense, their job first and foremost is to be artistically pleasing, they just have to fly as well. You might see entries that evoke the comical failed flying machines of yore with rotating umbrellas, eggbeater looking propellers, venetian blind treadmill wings. It might look like something Dr Seuss would design or some wispy, gossamer, feathery affair. The sounds they emitted would be part of the art as well. Mufflers might be fitted with whistles for instance.

The flying art exhibit/competition could be held every once in a while at various parks around the world.

I think it would be different because the two disciplines of art and aeronautics are such intellectual polar opposites. Bringing the two together in a ying yangy fashion might yield some interesting results.