Anna Pavlova, the famous Russian ballerina, died unexpectedly due to illness in 1931. On the occasion of the next ballet performance when she would have been dancing, the show went on, and when the time came for Anna to enter, they shined a single spotlight on the empty ballet stage where she would have been. They played the music and moved the spotlight to the normal cues. No dancer. An absence of something that is the something. Like the color black.