The clavioline is an electronic keyboard instrument, a forerunner to the analog synthesizer. It was invented by French engineer Constant Martin in 1947 in Versailles. The instrument consists of a keyboard and a separate amplifier and speaker unit. The keyboard usually covered three octaves, and had a number of switches to alter the tone of the sound produced, add vibrato (a defining feature of the instrument), and provide other effects. The Clavioline used a vacuum tube oscillator to produce a buzzy waveform, almost a square wave, which could then be altered using high-pass and low-pass filtering, as well as the vibrato. The amplifier also aided in creating the instrument's signature tones, by deliberately providing a large amount of distortion. Several models of the Clavioline were produced by different companies. Among the more important were the Standard, Reverb, and Concert models by Selmer in France and Gibson in the United States in the 1950s. The six-octave model employing octave transposition was developed by Harald Bode, and under licensed by Jörgensen Electronic in Germany. In England, the Jennings Organ Company's first successful product was the Univox, an early self-powered electronic keyboard inspired by the Selmer Clavioline. In Japan, Ace Tone's first prototype, the Canary S-2 (1962), was based on the Clavioline. Recordings The Clavioline has been used on a number of recordings in popular music as well as in film. Along with the Mellotron, it was one of the keyboard instruments favoured by rock and pop musicians during the 1960s before the arrival of the Moog synthesizer. "Little Red Monkey" (1953) by Frank Chacksfield’s Tunesmiths features Jack Jordan on clavioline. An earlier recording of the tune by Jack Jordan himself was issued on the HMV label. In 1953–54, Van Phillips composed music for the clavioline for the science-fiction radio trilogy Journey into Space. In the Bollywood Hindi film Nagin (1954), Kalyanji Virji Shah plays the snake-charmer tune "Man dole mera, tan dole mere" on the clavioline, under the musical direction of Hemant Kumar. "Runaway" and "Hats Off to Larry" (1961) by Del Shannon each feature a bridge solo by Max Crook, performed on a heavily modified clavioline that he called the Musitron. English producer Joe Meek began recording with a clavioline in 1960. His production of the Tornados' hit instrumental "Telstar" (1962) features the clavioline or perhaps a Univox, as does the B-side of that single, "Jungle Fever". Author Mark Brend states