A manual organ is an organ equipped with one or more manuals, which are specialized keyboards designed to be played by the hands. The term "manual" itself originates from the Latin word manus, meaning "hand."
Understanding the Manual
In the context of an organ, a manual serves as the primary interface for a performer's hands, allowing them to control various sets of pipes and create complex musical textures. Unlike a piano, where each key directly strikes a hammer, an organ manual activates a mechanism (traditionally mechanical, now often electronic) that opens valves, allowing air to flow through selected organ pipes.
Key Characteristics of Manuals
- Hand-Played Keyboards: The defining characteristic is that they are operated by the musician's hands.
- Multiple Keyboards: Organs often feature multiple manuals, stacked one above another. For instance, an organ with four distinct keyboards is described as having "four manuals." Each manual can be assigned to control different divisions of the organ (e.g., Great, Swell, Choir, Solo), each with its own unique tonal qualities and sets of stops.
- Control over Organ Stops: Alongside the keys, manuals are typically accompanied by various stops or registers that allow the organist to select which ranks of pipes will sound, thus altering the timbre and volume of the instrument.
Manuals vs. Pedalboards
While manuals are played by the hands, most organs also incorporate a pedalboard. This is a large keyboard, typically radiating outwards or parallel, designed to be played by the organist's feet. The pedalboard controls the lowest-pitched pipes of the organ, providing the bass foundation for the music. The interaction between the hands on the manuals and the feet on the pedalboard allows for a rich and full harmonic sound.
| Feature | Manual | Pedalboard |
|---|---|---|
| Played By | Hands (from Latin manus) | Feet |
| Purpose | Controls various pipe divisions, melodic and harmonic lines | Provides bass foundation, controls lowest-pitched pipes |
| Location | Stacked horizontally, above the pedals | Below the manuals, on the floor |
Significance in Organ Music
The presence of multiple manuals allows organists to:
- Switch rapidly between different timbres: Each manual can be pre-set with different combinations of stops.
- Layer sounds: Play different musical lines simultaneously on separate manuals, creating contrasting textures.
- Execute complex polyphony: Distribute voices across different keyboards for clarity and separation.
Understanding the function of manuals is fundamental to appreciating the intricate design and vast expressive capabilities of the organ.
