Polyphon Musik Automat, Musical Box

The Polyphon is a mechanical musical instrument featuring interchangeable metal discs, manufactured in Leipzig, Germany, by the company that adopted the name Polyphon Musikwerke AG in 1895. Its origins date back to the late 1880s: the instrument was presented at the Leipzig Autumn Fair in 1890, and the Polyphon trademark was registered the following year.
Its operation is based on a perforated metal disc: as the disc rotates, the projections on its surface activate a mechanism that causes the tuned steel teeth of a comb to vibrate, transforming the information encoded on the disc into music. The discs could be easily replaced, allowing different melodies to be played.
Larger models, such as the Musik Automat machines designed for public venues, represented a pioneering form of automatic musical entertainment. Installed mainly in restaurants and entertainment venues, they could be activated by inserting a coin; some models allowed users to choose between several melodies and featured a mechanism capable of automatically retrieving a disc from the storage compartment, playing it and returning it once the performance was complete.
The instrument achieved remarkable success: by the end of the 19th century, Polyphon had become an internationally significant industrial enterprise and, around 1900, employed approximately 800 people, with an annual production of around 40,000 instruments. Polyphon machines were also presented at the Paris Universal Exhibition of 1900.