Opera is the 13th Expert stage in Super Monkey Ball 2 and the 32nd Expert stage in Super Monkey Ball Deluxe. It also appears as the 142nd Ultimate stage with continues and the 182nd without continues.
This stage consists of two staircases going in wavelike directions. After you make it through the first section of staircases, the angle of the staircases becomes steeper. The goal lies in the middle and at the base of the last circle.
Go down either one of the two staircases, and make your way down. Since the slopes of the stairs get steeper on the way down, eventually slow your speed more, or you may fall off the stage. Be careful when you arrive at the goal as it is easy to be bounced off by it due to speed.