Manual

The keyboards on an organ are called manuals. (Or perhaps you were looking for a ServiceManual?)

The manuals on a Hammond are called the Great or lower keyboard and the Swell or upper keyboard. In pipe organs, the Great is the primary playing keyboard. It typically has more stops playing more ranks of pipes than other manuals. The Swell keyboard typically plays pipes enclosed in a sound chamber with shutters that can be opened and shut by the Swell or expression pedal. Some pipe organs have a third manual, usually called the Choir; more manuals (up to seven) are sometimes present on unusually large instruments.

The most popular Hammonds have what are called Waterfall keys in the key manuals. WaterfallKeys are squared off, somewhat like a piano, but without the horizontal protruding lip on the playing surface of the key that all piano keyboards have. It is often stated reason for this design was that LaurensHammond was not a musician and he used a piano keyboard in his prototypes. But the key reason was that they were cheaper to build. The naturals have a lip underneath the key that normally resets on the ?UpStopFelts that are fastened to the keyrails. This assures that the alignment of the naturals requires no adjustment and thus saves the labor costs to do so.

But Waterfall keys are quite a different design than the keyboards of pipe organs. Pipe organ keyboards often have a shape refered to as a Divingboard. DivingBoardKeys are easier to overhang the key manuals to allow a player to play two keyboards with one hand. The Hammond "Waterfall" keys, keyrail and the ?Busbars beneath each manual made it difficult to overhang the key manuals. So Hammond manuals are stepped rather than overhung.

Later, when Hammond began selling ConcertOrgans and late model SpinetOrgans, the waterfall keys were replaced with divingboard keys. However, most Jazz, Pop and Rock musicians prefer the waterfall keys on the ConsoleOrgans which makes certain techniques, such as smears and palm wipes, easier to execute. A diving board key has a sharply defined edge which can actually cut the hand when these techniques are used.