He was eventually part of Emerson, Lake and Palmer which formed in 1970.
The band became very popular after playing at the Isle of Wiight concert in 1970. The band continued to release successful albums until they disbanded in 1979.
The group only ever had one single hit in the UK charts in the 1970s and that was Fanfare For The Common Man from the 1977 album Works Volume.
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With ELP, Emerson added the Moog
behind the C-3 with the keyboard and ribbon controller stacked on the top of the organ. The ribbon controller allowed Emerson to vary synthesiser , volume or timbre of the output from the Moog by moving his finger up and down the length of a touch-sensitive strip. It also could be used as a phallic symbol, which quickly became a feature of the act. When the Minimoog entered the act it was placed where needed, such as on top of the grand piano. The same location was also used for an electric Clavinet keyboard, used almost exclusively for the encore piece "Nut Rocker". pitch
During the Brain Salad Surgery tour of 1974 (one show of which was documented on the 3-LP set, Welcome Back My Friends, to the Show That Never Ends), Emerson's keyboard setup included the Hammond C-3 organ, run through multiple Leslie speakers driven by HiWatt guitar amplifiers, the Moog 3C modular synthesiser (modified by addition of various modules and an oscilloscope) with ribbon controller, a Steinway concert grand piano with a Moog Minimoog synthesiser on top of it (used for the steel drum part on Karn Evil 9, 2nd Impression), an upright acoustic-electric piano that was used for honky-tonk piano sounds, a Hohner Clavinet and another Moog Minimoog synthesiser. Emerson also used a prototype polyphonic
produced by Moog, which was the test bed for the Moog Polymoog polyphonic synthesiser . The original synthesiser setup as envisioned by Moog was called the Constellation, and consisted of three instruments – the polyphonic synthesiser , called the Apollo, a monophonic lead synthesiser called the Lyra, and a bass-pedal synthesiser , called the Taurus. Moog eventually produced the Moog Taurus bass pedal synthesiser as a separate instrument, as well as the Polymoog synthesiser and Polymoog Keyboard. The Apollo polyphonic Synthesiser is currently at a keyboard museum in Calgary, Alberta, Canada. Emerson still owns the Lyra synthesiser . synthesiser
Occasionally Emerson used a pipe organ, when available. In particular, at the Newcastle City Hall he used the Harrison & Harrison pipe organ
for the introductory section of Pictures at an Exhibition. The organ is located at the rear above the stage, at the top of a series of steps where choirs can stand. The end of the introductory passage is followed by a drum roll, covering the time while Emerson descended the steps. While all went well for the recording used to produce the album, the debut tour performance at the same venue ground to a halt as the power failed, just as Emerson arrived at the Hammond organ to open the next part of the piece. After a lengthy delay the performance continued with only the Hammond L-100 functioning.