Hammond organ

The Hammond organ is an electric organ invented by Laurens Hammond and John M. Hanert, first manufactured in 1935. Multiple models have been produced, most of which use sliding drawbars to vary sounds. Until 1975, sound was created from rotating a metal tonewheel near an electromagnetic pickup, and amplifying the electric signal into a speaker cabinet. The organ is commonly used with the Leslie speaker.

Around two million Hammond organs have been manufactured. The organ was originally marketed by the Hammond Organ Company to churches as a lower-cost alternative to the wind-driven pipe organ, or instead of a piano. It quickly became popular with professional jazz musicians in organ trios—small groups centered on the Hammond organ. Jazz club owners found that organ trios were cheaper than hiring a big band. Jimmy Smith's use of the Hammond B-3, with its additional harmonic percussion feature, inspired a generation of organ players, and its use became more widespread in the 1960s and 1970s in genres such as rhythm and blues, rock (especially progressive rock), and reggae.

In the 1970s, the Hammond Organ Company abandoned tonewheels and switched to integrated circuits. These organs were less popular, and the company went out of business in 1985. The Hammond name was purchased by the Suzuki Musical Instrument Corporation, which proceeded to manufacture digital simulations of the most popular tonewheel organs. This culminated in the production of the "New B-3" in 2002, a recreation of the original B-3 organ using digital technology. Hammond-Suzuki continues to manufacture a variety of organs for both professional players and churches. Companies such as Korg, Roland, and Clavia have achieved success in providing more lightweight and portable emulations of the original tonewheel organs, called clonewheel organs. The sound of a tonewheel Hammond can be emulated using modern software audio plug-ins.

The Hammond organ has features not typically found on the piano or synthesizer. Some are similar to a pipe organ, but others are unique to the instrument.

Most Hammond organs have two 61-note (five-octave) keyboards called manuals. As with pipe organ keyboards, the two manuals are positioned on two levels close to each other. Each is laid out in a similar manner to a piano keyboard, except that pressing a key on a Hammond results in the sound continuously playing until it is released, whereas with a piano, the note's volume decays. No difference in volume occurs regardless of how heavily or lightly the key is pressed (unlike with a piano), so overall volume is controlled by a pedal (also known as a "swell" or "expression" pedal). The keys on each manual have a lightweight action, which allows players to perform rapid passages more easily than on a piano. In contrast to piano and pipe organ keys, Hammond keys have a flat-front profile, commonly referred to as "waterfall" style. Early Hammond console models had sharp edges, but starting with the B-2, these were rounded, as they were cheaper to manufacture. The M series of spinets also had waterfall keys (which has subsequently made them ideal for spares on B-3s and C-3s), but later spinet models had "diving board" style keys which resembled those found on a church organ. Modern Hammond-Suzuki models use waterfall keys.

Hammond console organs come with a wooden pedalboard played with the feet, for bass notes. Most console Hammond pedalboards have 25 notes, with the bottom note a low C and the top note a middle C two octaves higher. Hammond used a 25-note pedalboard because he found that on traditional 32-note pedalboards used in church pipe organs, the top seven notes were seldom used. The Hammond Concert models E, RT, RT-2, RT-3 and D-100 had 32-note American Guild of Organists (AGO) pedalboards going up to the G above middle C as the top note. The RT-2, RT-3 and D-100 also contained a separate solo pedal system that had its own volume control and various other features. Spinet models have 12- or 13-note miniature pedalboards.

Hammond organ manuals and pedalboards were originally manufactured with solid palladium alloy wire to ensure a high-quality electrical connection when pressing a key. This design was discontinued with the introduction of the transistor organ. This means tonewheel organs have between 3.2 and 8.4 grams of palladium, depending on make and model.

The sound on a tonewheel Hammond organ is varied through the manipulation of drawbars. A drawbar is a metal slider that controls the volume of a particular sound component, in a similar way to a fader on an audio mixing console. As a drawbar is incrementally pulled out, it increases the volume of its sound. When pushed all the way in, the volume is decreased to zero.