This challenge is very difficult for me to come out an idea to do it... In the end, I decide to duplicate chairs, fance, stair and make it become a fancy show theater.The following is my first draft(March30), but I feel the overall color is a little bit monotone, and he chair and curtain's shading is not right. I'll try to fix it in the later day.
april 1st update
I add "color cuvre" to some lights toenrich the light color, and add a Depth of field, as well as paint a character on the stage.