A musical instrument which plays a musical composition programmed on a pinned cylinder, disc, music roll, or other medium, and which usually requires no musical knowledge on the part of the operator. A self-playing or mechanical musical instrument. The term "automatic" was originally used to describe all types of self-playing instruments. Although the term "mechanical" is often used synonymously today, "mechanical" was not generally used originally to describe instruments with sophisticated expression capabilities (e.g., certain large orchestrions, player pipe organs, reproducing pianos). Motive power for an automatic musical instrument may be provided by a hand crank, spring-wound clockwork, a weight-driven system, an electric motor, a water motor, a foot pump, or by other means.