Three musicians are on stage. Let us say it is a piano trio. They start concentrating, signaling that a performance has started. There is a long silence. Then the cello plays a sound, a simple note on the A string, lasting just a few seconds. Again, a silence – it is hard to tell how long exactly. It could be a minute, it could be many minutes. Then, out of nowhere, a piano note sounds, at the same pitch as the cello note heard before. Silence once more. Then, at some moment, the performers look at one another, and relax. Apparently, the piece is over. The violin has not played at all.