A single motor drives eight chain loops, each of which is responsible for periodically lifting and dropping a mallet that sounds one note of a glockenspiel. Each successive chain is one link shorter than the last. As they loop around they fall ever further out of sync resulting in a unique changing melody.
If it could run indefinitely the musical sequence would only repeat every 1,300 years, beginning with all notes chiming in unison.
The audience experiences the changing riffs and rhythms in the meantime. Patterns form and gradually fall away as complex new melodies emerge from the interaction of these simple rules.