A reproach currently made to music boxes is the difficulty experienced in changing the piece of music to be played. On of the solutions proposed was to note the popular tunes on metal discs; they thus became easier to handle. This model for cafes and other public places has a coin-slot but more particularly a mechanism for selecting and changing a disc automatically. The Polyphon firm was founded in 1868 by two men who had previously worked for Paul Lochman. They employed more than two thousand people in the factory on the outskirts of Leipzig.