Dance of Switched Heads

It was autumn, in a crowded midwestern basement full of people listening to indistinguishable rock bands perform, until something else happened. Two percussionists began to play while the audience was led upstairs to sit on the floor directly above the performers. Two more percussionists sat among the audience and played their parts accordingly. When the piece ended, the performers immediately left, no one knowing who they were or why they were there.