The metronome is a true chameleon—originally invented in the 17th century as a mechanical pendulum, it has adapted to every technological invention. It now refers to a mechanical, electronic, and even digital timepiece that uses acoustic impulses to set a constant tempo. It also symbolizes the much-discussed interaction between man and machine: the machine sets the beat and the man reacts. As a rhythm training device, Metronome aims to create a joy of rhythm. The louder and faster you clap or chime along, the denser the graphics become. The metronome is both fun and comforting: the more wildly and imprecisely you play, the more beautiful the images, while the more precise the rhythm, the less interesting the visual events become. Perhaps the theory is true that emotion can only be created by impreciseness.