In addition to drawbars, many Hammond tonewheel organ models also include presets, which make predefined drawbar combinations available at the press of a button. Console organs have one octave of reverse colored keys (naturals are black, sharps and flats are white) to the left of each manual, with each key activating a preset; the far left key (C), also known as the cancel key, de-activates all presets, and results in no sound coming from that manual. The two right-most preset keys (B and B♭) activate the corresponding set of drawbars for that manual, while the other preset keys produce preselected drawbar settings that are internally wired into the preset panel.[20]
来源:https://en.wikipedia.org/wiki/Hammond_organ