Manual (music)

Music written to be played only on the manuals (and not using the pedals) can be designated by the word manualiter (first attested in 1511, but particularly common in the 17th and 18th centuries).

Changes in registration through use of drawknobs, stop tabs, or other mechanisms to control organ stops allow such instruments to achieve an aggregate range well in excess of pianos and other keyboard instruments even with manuals of shorter pitch range and smaller size.On smaller electronic organs and synthesizers, the manuals may span fewer octaves, and they may also be offset, with the lower one an octave to the left of the upper one.

On digital synthesizer instruments a performer can produce the sounds of an entire orchestra through the use of all available manuals in conjunction with the pedalboard and the various registration controls.

The exception is some modern electronic instruments and relatively contemporary upgrades to theatre pipe organ consoles, which may have a knee lever which sustains the previous chords or notes.

Some modern electronic instruments allow for volume to vary with the force applied to the key and permit the organist to sustain the note and alter both its attack and decay in a variety of ways.

For example, Hammond organs often have an expression pedal, which enables the performer to increase or decrease the volume of a note, chord, or passage.

Various other controls, such as stops, pistons, and registration presets are usually located adjacent to the manuals to allow the organist ready access to them while playing.

This further increases the instrument's versatility, as a piston or other preset function can cause multiple stops to be pulled out or pushed in automatically.