The Moog synthesizer consists of separate modules which create and shape sounds, which are connected via patch cords.

Moog developed the synthesizer in response to demand for more practical and affordable electronic music equipment, guided by suggestions and requests from composers including Herb Deutsch, Richard Teitelbaum, Vladimir Ussachevsky and Wendy Carlos.

Mort Garson used the Moog to soundtrack the televised Apollo 11 moonwalk, associating synthesizers with space in the popular imagination.

In the late 1960s, it was adopted by rock and pop acts including the Doors, the Grateful Dead, the Rolling Stones and the Beatles.

At its height of popularity, it was a staple of 1970s progressive rock, used by acts including Yes, Tangerine Dream and Emerson, Lake & Palmer.

With its ability to imitate instruments such as strings and horns, it threatened the jobs of session musicians and was banned from use in commercial work for a period of time in the United States.

Recognizing the need for more practical and sophisticated equipment, Moog and Deutsch discussed the notion of a "portable electronic music studio".

[5] Learning from his experience building a prohibitively expensive guitar amplifier, he believed that practicality and affordability were the most important parameters.

Moog designed his synthesizer around a standard of one volt per octave, and used voltage to control loudness with voltage-controlled amplifiers (VCAs).

[3] According to Moog, when Deutsch saw this, he became excited and immediately began making music with the prototype, attracting the interest of passersby: "They would stand there, they'd listen and they'd shake their heads ... What is this weird shit coming out of the basement?

[3] With no books and no way to save or share settings, early users had to learn how to use the synthesizer themselves, by word of mouth, or from seminars held by Moog and Deutsch.

[3] At the suggestion of the composer Gustav Ciamaga, Moog developed a filter module, a means of removing frequencies from waveforms.

He later developed the distinctive "ladder" filter, which was the only item in the synthesizer design that Moog patented, granted on October 28, 1969.

[3] Moog initially avoided the word, as it was associated with the RCA synthesizer, and instead described his invention as a "system" of "electronic music modules".

[4] Whereas the RCA Mark II was programmed with punchcards, Moog's synthesizer could be played in real time via keyboard, making it attractive to musicians.

[6] The authors of Analog Days wrote: "Though the notion of voltage control and Moog's circuit designs were not original, Moog's innovations were in drawing the elements together, realizing that the problem of exponential conversion could be solved using transistor circuitry and building such circuits and making them work in a way that was of interest to musicians.

"[3] Moog features such as voltage-controlled oscillator, envelopes, noise generators, filters and sequencers became standards in the synthesizer market.

[17] The composer Mort Garson recorded the first album on the West Coast to use the Moog synthesizer, The Zodiac: Cosmic Sounds (1967).

In 1969, Garson used the Moog to compose a soundtrack for the televised footage of the Apollo 11 moonwalk, creating a link between electronic music and space in the American popular imagination.

[citation needed] An early use of the Moog synthesizer in rock music came with the 1967 song by the Doors "Strange Days".

[22] In later decades, hip hop groups such as the Beastie Boys and rock bands including They Might Be Giants and Wilco "revived an interest in the early Moog synthesizer timbres".

[7] The Guardian wrote that the Moog synthesizer, with its dramatically new sounds, arrived at a time in American history when, in the wake of the Vietnam War, "nearly everything about the old order was up for revision".

For a period, the Moog was banned from use in commercial work in the US, a restriction negotiated by the American Federation of Musicians (AFM).