What exactly is a square piano?

“Square pianos” are keyboard instruments developed in the mid-18th century that enjoyed tremendous popularity in England, Europe, and America into the early 19th century. Although luminaries such as Queen Charlotte of England, author Jane Austen, and Presidents George Washington and Thomas Jefferson all had square pianos, these instruments owed their popularity primarily to the thousands of amateur musicians who purchased these relatively inexpensive instruments for music making at home.

Square pianos aren’t actually square. They consist of a rectangular case mounted on four legs with a keyboard of between five and five and one-half octaves, shorter than today’s piano of seven and a quarter octaves. Inside the case are horizontal strings set diagonally together with a sounding board. When a key is pressed by the player a hammer strikes the string, making it sound. This makes the square piano similar to a modern piano but different from its contemporary, the harpsichord, where the strings are plucked by a small part called a plectrum. All pianos use this striking hammer action. In fact, pianos are considered to be both stringed and percussion instruments. Square pianos provided the player with opportunities to vary the sound by using a variety of pedals and hand operated “stops” which could make the strings vibrate longer or produce a more muted sound. Advances in technology and construction materials enabled piano makers to further develop pianos in the 19th century, and square pianos were gradually superseded by larger, more powerful instruments. Fortunately, examples of early square pianos have survived, which allows us to hear music composed for them as it was intended to be heard.

The square piano (from 1815) played in the video below is very similar to the one (from 1814) that will be featured in our upcoming spring benefit.