The Mellotron is an electro-mechanical, polyphonic keyboard originally developed and built in Birmingham, England in the early 1960s. It superseded the Chamberlin, which was the world’s first sample-playback keyboard. The heart of the instrument is a bank of parallel linear magnetic audio tape strips. Playback heads underneath each key enable the playing of pre-recorded sounds. Each of the tape strips has a playing time of approximately eight seconds, after which the tape comes to a dead stop and rewinds to the start position.
A major advantage of using tape strips, as opposed to tape loops or cassettes (cf. the Birotron) is that the Mellotron can reproduce the attack and decay of the instruments recorded on the tape.
A consequence of the eight second limit on the duration of each note is that if one wants to play chords that last longer than eight seconds, one must release different notes in sequence in a process that has been compared to a spider crawling across the keyboard.
The earlier MKI and MKII models contained two side-by-side keyboards: The right keyboard accessed 18 “lead/instrument” sounds such as strings, flutes, and brass; The left keyboard played pre-recorded musical rhythm tracks in various styles.
The tape banks for the later, lighter-weight M400 models contain only three selectable sounds including (typically) strings, cello, and an eight-voice choir. The sound on each individual tape piece was recorded at the pitch of the key to which it was assigned. To make up for the fewer sounds available, the M400 tapes came in a removable frame that allowed for relatively quick changes to new racks of sounds.
Although tape samplers had been explored in research studios, the first commercially available keyboard-driven tape instruments were built and sold by California-based Harry Chamberlin from 1948 through the 1970s
Things really took off, however, when Chamberlin’s sales agent, Bill Fransen, brought two of Chamberlin’s instruments to England in 1962 to search for someone who could manufacture 70 matching tape heads for future Chamberlins. Harry Chamberlin was unhappy with the fact that someone overseas was copying his idea, and that one of his own people (Bill Fransen) was the reason for this. Fransen approached a UK company that was skilled enough to develop the idea further and a deal was struck with brothers Frank, Norm, and Lesley Bradley of engineering company Bradmatic Ltd. This resulted in the formation of a subsidiary company named Mellotronics, which produced the first Mellotrons in Aston, Birmingham, England. The music sessions for Mellotrons were recorded by the Eric Robinson Organisation at IBC Studios, 35 Portland Place in London England. Mellotronics had offices there and the recordings were made using a customized 9 into 3 recording desk built by IBC’s Denis King. Magician David Nixon partly funded it. Manufacturing company Bradmatic later took on the name Streetly Electronics. In the early 1970s 100 of the instruments were assembled and sold by EMI under exclusive license. Many years later, following financial and trademark troubles through a U.S. distribution agreement, the Mellotron name became unavailable and resided with the American based Sound Sales, and later manufactured by Bomar Fabricating Ltd. while Streetly manufactured instruments after 1976 were sold under the name Novatron.
Throughout the 1970s, the Mellotron had a major impact on rock music, particularly the 35 note (G-F) model M400. The M400 version was released in 1970 and sold over 1800 units, becoming a trademark sound of the era’s progressive bands. The earlier 1960s MK II units were made for the home and the characteristics of the instrument attracted a number of celebrities. Among the early Mellotron owners were Princess Margaret, Peter Sellers, King Hussein of Jordan and Scientology founder L. Ron Hubbard.
Mellotrons were normally pre-loaded with string instrument and orchestral sounds, although the model 400’s tape bank could be removed with relative ease by the owner and loaded with banks containing different sounds including percussion loops, sound effects, or synthesizer-generated sounds, to generate polyphonic electronically generated sounds in the days before polyphonic synthesizers.
In the late 1990s, a Calgary-based company began producing new Mellotrons. These new MKVI Mellotrons were similar to the M400, with some modifications. The company also released sample discs featuring WAV files of each individual note sampled from an original Mellotron. These files, when played using a sampler, enable keyboardists to recreate a part of the sound of the original Mellotrons using cheaper and more reliable modern keyboards.
In 2009, Streetly Electronics released the M4000. The most recent machine to offer a cycling mechanism, an updated design of the system used in the 1960s MK 1, MK 2 and M300 machines.