Main manual (Great)
The main keyboard of the organ intended for playing with the hands, with the most powerful stops.
What it means
The main manual (Hauptmanual) is the principal keyboard of an organ, played with the hands. The most powerful and important stops are assigned to it, so it delivers the full, carrying sound of the organ. Larger organs have several manuals, of which the main manual forms the core.
Musical use
In organ building the main manual is often assigned to the Great division (Hauptwerk), the sonically strongest part of the organ with principals, octaves, and mixtures. It usually lies as the second manual from below and is complemented by further manuals such as Swell, Positive, and Choir, which offer other tone colors. When playing, organists change between the manuals to separate melody and accompaniment in sound.
The main manual should be distinguished from the pedal, the keyboard played with the feet, and from the secondary manuals, which are registered more quietly, more colorfully, or more soloistically. It also differs from a piano keyboard because the keys act on pipe valves rather than hammers.
Performance practice
Choose a registration for the main manual that suits the character of the piece and begin with foundation stops before adding overtone stops. Aim for an even, articulated touch, since the organ forgives no imprecision and joins notes differently from the piano.