On a Hammond organ with tonewheels, a slider that shortens the distance between the axle bearing the wheels and the transducer which converts their spinning patterns into an audio signal. This has the effect of introducing a particular harmonic into the sound to alter its timbre. While similar in purpose to a stop on a pipe organ, it has the advantage of being variable in intensity as opposed to a stop’s simple on/off action. Drawbars have been retained on more recent electronic organs of the Hammond type, but their function is now to act as simple faders that adjust the gain of different oscillators.