I've been to a concert that had an upright piano rolling around the stage, being upside down at several points. Apparently getting it to work involved installin

I've been to a concert that had an upright piano rolling around the stage, being upside down at several points. Apparently getting it to work involved installing some extra springs in the piano. Unrelatedly they also had a trick piano where the whole backside and frame with strings would detach at the climax of the song and come crashing down to the floor on cue. Apparently they didn't need to tune the piano used for that an abnormal amount.