The pedal piano (or piano-pédalier or pédalier,) is a kind of piano that includes a pedalboard, enabling bass register notes to be played with the feet, as is standard on the organ. There are two broad types of pedal pianos: either the pedal board may be an integral part of the instrument, using the same strings and mechanism as the manual keyboard (e.g. the 19th century Érard pedal grand piano and Pleyel upright pedal piano), or it may consist of two independent pianos (each with its separate mechanics and strings) which are placed one above the other, either a regular piano played by the hands and a bass-register piano played by the feet (e.g. the 18th century pedal piano owned by Wolfgang Amadeus Mozart and the 21st century Doppio Borgato made by Luigi Borgato), or two standard pianos of which the lower one is played from a pedalboard which acts on its (manual) keyboard through a special mechanism (e.g. the 21st century Pinchi Pedalpiano System). History The origins of the pedal piano are found in the pedal clavichord and pedal harpsichord, of which an original of the former survives while only descriptions and modern reproductions of the latter remain. The first citation of a clavichord with pedalboard appeared around 1460 in a section dedicated to musical instruments in an encyclopedic treatise written by the scholar Paulus Paulirinus (1413-1471). Organists would use these instruments for practice when no-one was available to work the bellows for a church organ or, in the wintertime, to avoid having to practice in an unheated church. Johann Sebastian Bach owned a pedal harpsichord, and his organ trio sonatas BWV 525–530, Passacaglia and Fugue in C minor BWV 582, and other works can be played on the instrument. Wolfgang Amadeus Mozart owned a fortepiano with independent pedals, built for him in 1785 by Anton Walter. His father refers to this in a letter to his daughter on March 12, 1785. The autographed manuscript of the Concerto in D minor K 466, composed the same year, shows a series of chords for the left hand plus bass notes an octave lower, covering about 2 1/2 measures. Some believe that the bass notes were intended for the pedal, but there is disagreement about this interpretation. The additional bass notes could be regarded as the original version which was not crossed out when Mozart decided to replace them with chords.