(Advertisement from The Music Trade Review, 1920.)
This advertisement by the Monarch Tool & Mfr. Company is from The Music Trade Review of February, 1920. It shows the style of remote wall boxes made by Monarch, for which multiple wall boxes could be placed throughout a restaurant or saloon. Inside the cast iron box was a simple electrical contact that was momentarily actuated when struck by a coin. The coin magazine in the piano was then tripped using a electromagnet, which was wired in series with battery and a wall box, or a group of wall boxes that were all wired together in parallel. This arrangement made it easy for patrons to drop a coin at various convenient locations and have the connected automatic piano or orchestrion play, rewarding the customer with a happy tune.