The fingerboard of a piano, organ, or other keyboard instrument.A unique set of strings on the baryton. The upper manual refers to the bowed strings on the front of the fingerboard and the lower manual refers to the sympathetic and plucked strings behind the fingerboard. Occasionally, a third manual was used.the manual is a keyboard for the hands, the word used for instruments such as the organ or harpsichord that often have more than one keyboard. It is opposed to the pedal-board found generally on the organ and much more rarely on the harpsichord or fortepiano.