Square piano

The square piano is a piano that has horizontal strings arranged diagonally across the rectangular case above the hammers and with the keyboard set in the long side, with the sounding board above a cavity in the short side. It is variously attributed to Silbermann and Frederici and was improved by Petzold and Babcock. The English and Viennese square pianos were built in many different designs, including within the action as well as general appearance, from roughly 1760. Because of the competitive industry and relative youth of the instrument design itself, experimentation ensued in the early years, creating a range of moderators and other technical devices not seen today. In London, the explosion of the trade is generally attributed to the maker Zumpe. The overwhelming popularity of his instruments was due to inexpensive construction and price. In the 1860s metal frames were developed for square pianos, meaning that higher string tensions and therefore greater volumes were possible; however the size increases meant that the upright piano design was more economical, and so the upright replaced the square as the most common home instrument.