A manual is any hand-operated keyboard on a keyboard instrument that either has a pedalboard or has more than one hand-operated keyboard.
An electronic organ with three manuals. The two lower manuals are each five octaves in range, while the uppermost manual spans two octaves.
The organ console in St. Mary Redcliffe church in Bristol, England, with four manuals.
A 1970s-era Fairlight synthesizer with two manuals.
A three manual digital synthesizer organ.
A harpsichord is a keyboard instrument that makes its sound by plucking a set of strings. In a harpsichord, depressing a key raises its back end within the instrument, which in turn lifts one or more
Manual (music)
…a keyboard on which notes are played with the feet, such as an organ) or has more than one hand-operated keyboard (such as a two- or three-manual harpsichord). (On instruments that have neither a pedalboard nor more than one hand-operated keyboard, the word "manual" is not a synonym for "keyboard".) Music…
This harpsichord is the work of two celebrated makers: originally constructed by Andreas Ruckers in Antwerp (1646), it was later remodeled and expanded in a process called grand ravalement by Pascal Taskin in Paris (1780).
An early diagram of a vertical harpsichord (clavicytherium) by Arnault de Zwolle, c. 1430
Harpsichord by Christian Zell, at Museu de la Música de Barcelona. From upper left to lower right: a bridge (supporting the far ends of the strings), the jack rail with the action (jacks) underneath, two nuts (supporting the closer ends of the strings), interleaved with two rows of tuning pins, and finally the keyboard. As with all harpsichords, the action itself is mostly hidden by the jack rail when the instrument is being played; only by removing the jack rail (or indeed, by extracting a jack) can the details of the action be observed.
Sound board of a harpsichord with Chladni patterns