An electronic organ is an electronic keyboard instrument which was derived from the harmonium, pipe organ and theatre organ. Originally, it was designed to imitate the sound of pipe organs, theatre organs, band sounds, or orchestral sounds.

Today, it has developed into three or more types of instruments;

The immediate predecessor of the electronic organ was the harmonium, or reed organ, an instrument that was very popular in homes and small churches in the late nineteenth and early twentieth centuries. In a fashion not totally unlike that of pipe organs, reed organs generated sound by forcing air over a set of reeds by means of a bellows, usually operated by constantly pumping a set of pedals. While reed organs had limited tonal quality, they were small, inexpensive, self-powered, and self-contained. The reed organ was thus able to bring an organlike sound to venues that were incapable of housing or affording pipe organs. This concept was to play an important role in the development of the electric organ.

Herbert Jeffrey "Herbie" Hancock (born April 12, 1940) is an American pianist, keyboardist, bandleader and composer. As part of Miles Davis's Second Great Quintet, Hancock helped to redefine the role of a jazz rhythm section and was one of the primary architects of the "post-bop" sound. He was one of the first jazz musicians to embrace music synthesizers and funk music (characterized by syncopated drum beats). Hancock's music is often melodic and accessible; he has had many songs "cross over" and achieved success among pop audiences. His music embraces elements of funk and soul while adopting freer stylistic elements from jazz. In his jazz improvisation, he possesses a unique creative blend of jazz, blues, and modern classical music, with harmonic stylings much like the styles of Claude Debussy and Maurice Ravel.

Hancock's best-known solo works include "Cantaloupe Island", "Watermelon Man" (later performed by dozens of musicians, including bandleader Mongo Santamaría), "Maiden Voyage", "Chameleon", and the singles "I Thought It Was You" and "Rockit". His 2007 tribute album River: The Joni Letters won the 2008 Grammy Award for Album of the Year, only the second jazz album ever to win the award after Getz/Gilberto in 1965.