Hammond organ
An electromechanical organ using rotating tonewheels and electromagnetic pickups, whose rich, harmonically complex sound defined gospel, jazz, and rock music.
In Depth
Laurens Hammond invented the tonewheel organ in 1935 as an affordable alternative to pipe organs for churches. The instrument generates sound through spinning metal tonewheels near electromagnetic pickups, with drawbars allowing the player to mix different harmonic overtones in real time. The Leslie rotating speaker cabinet, which adds a distinctive tremolo-[chorus effect](/term/chorus%20effect), became inseparable from the Hammond sound. The Hammond B-3 model became the definitive instrument for gospel, jazz, R&B, and rock organ. Jimmy Smith brought it to jazz, while players like Keith Emerson, Jon Lord, and Gregg Allman made it essential to progressive and classic rock. The B-3 with a Leslie speaker remains one of the most sought-after keyboard instruments. Digital clones exist, but purists insist the mechanical warmth and response of original tonewheels is irreplaceable.
The Hammond organ uses 91 spinning metal tonewheels to generate sound — when powered up, the wheels take about 10 seconds to reach full speed, producing the instrument's characteristic start-up whine.