The Square Piano
Experiments were under way from early in the eighteenth century to produce a keyboard instrument which, unlike the harpsichord or spinet, would be capable of playing both loudly and softly - the forte piano or fortepiano.
In the early 1760's Johannes Zumpe in London started making small, rectangular five octave instruments which satisfied these requirements and became hugely popular. The demand for these small "square pianos" was enormous and manufacturers such as Adam Beyer, Christopher Ganer and John Broadwood began producing instruments in quantity.
Square piano by Bury c. 1786.
Cases of these square pianos varied from a simple mahogany instrument raised on a trestle stand, to one crossbanded in satinwood and raised on Sheraton style square tapered legs or with elaborate inlays of exotic timbers. The tone of the earliest square pianos was still reminiscent of the harpsichord or spinet but changes in the hammer coating rapidly produced a more 'pianistic' sound.
As the compass increased to five and a half octaves, so the case increased in size and the style became more typically Regency. Six legs became standard, either turned or turned and reeded. Cases could be of plain mahogany, or crossbanded in rosewood and with ornate brass mounts as decoration. Music drawers were another option.
Square piano by Tuck c. 1820
By the time the keyboard had extended to six octaves and beyond, the cases of the pianos had become much larger, usually with four rather solid looking legs. The tone was still exquisite, but more nearly aproaching the sound we associate with the "modern" piano.