The hardware version of the Mellotron is an electromechanical polyphonic keyboard musical instrument originally developed
and built in Birmingham, England in the early 1960s.

The Mellotron follows its direct ancestor the Chamberlin which was, in effect, the world's first sample-playback keyboard.
The heart of the instrument is a bank of magnetic audio tapes (these tapes were parallel linear, not looped as has sometimes
been reported or presumed), each tape with approximately eight seconds of playing time; playback heads underneath each
key enables performers to play the pre-recorded sound assigned to that key when pressed.

The earlier MKI and MKII models contained two side-by-side keyboards: On the right keyboard were 18 selectable
"lead/instrument" sounds (such as strings, flutes, and brass instruments). The left keyboard played pre-recorded musical
rhythm tracks (in various styles).

The tape banks for the later, lighter-weight M400 models contain only 3 selectable sounds such as strings, cello, and the
famous 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, which allowed for
relatively quick changes to new racks of sounds.
 
Although tape samplers had been explored in research studios (e.g., Hugh LeCaine's 1955 keyboard-controlled "Special
Purpose Tape Recorder", which he used when recording his classic "Dripsody"), 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 not at all happy at first with the fact that someone overseas was basically "copying" his idea, and that
one of his own people (Bill Fransen) was the reason for this. He eventually found a UK company that were skilled enough to
develop the idea further and a deal was struck with Bill and Lesley Bradley of tape recorder company Bradmatic Ltd. This
resulted in the formation of a subsidiary company named Mellotronics, which produced the first Mellotrons in Aston,
Birmingham, England. Bradmatic later took on the name Streetly Electronics. Many years later, following financial and
trademark troubles, the Mellotron name became unavailable and later instruments were sold under the name Novatron.
A small number of the instruments were assembled and sold by EMI under license.

Through the late 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 novel characteristics of the instrument attracted a number of celebrities, and 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 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.

The unique sound of the Mellotron is produced by a combination of characteristics: Among these are tape replay artifacts
such as wow and flutter, the result being that each time a note is played it is slightly different from the previous time it
was played (a bit like a conventional instrument). The notes also interact with each other so that chords or even just pairs
of notes have an extremely powerful sound. Another factor in the strangely haunting quality of the Mellotron's most
frequently-heard sounds is that the individual notes were recorded in isolation. For a musician used to playing in an
orchestral setting, this was unusual, and meant that he/she had nothing to intonate against. Thus, the temperament of the
mellotron is always somewhat questionable when it is used in the context of other instruments. Perhaps for this reason,
and perhaps also to allow easy transposition of the instrument's limited range, the pitch control is placed closest to the
keyboard on the M400 model. This temperament issue has led to the Mellotron being rather unfairly regarded as difficult
to tune. There certainly could be mechanical problems that would also contribute to this. The original varispeed servo
design was poor, for instance, but later improved dramatically. The tapes would stick inside their frames and refuse to
rewind if the frame became distorted due to careless handling of the machine. Properly maintained, though, the machines
behave a lot better than their reputation suggests.

Although they enabled many bands to perform string, brass and choir arrangements which had been previously impossible
to recreate live, Mellotrons were not without their disadvantages. Above all, they were very expensive – they sold for £1,000
in the mid-1960s, and the official Mellotron site gives the 1973 list price as US$5200. Like the Hammond organ they were
a roadie's nightmare – heavy, bulky and fragile. After years of touring with Mellotrons, Robert Fripp formulated a rule:
"Tuning a mellotron doesn't." The tape banks were also notoriously prone to breakages and jams and those groups who
could afford to (like Yes) typically took two Mellotrons on tour with them to cope with the inevitable breakdowns.

The original Mellotrons (MkI/MkII) were not intended to be portable (they often become misaligned when jostled even
lightly), but later models such as the M300, M400 and MkV were designed for portability. All models, when installed
permanently in a studio, provided a very realistic effect. An example of this can be found on Elton John's Goodbye
Yellow Brick Road album.

Despite these shortcomings, Mellotrons were prized for their unique sound, and they helped pave the way for the later
sampler.

British multi-instrumentalist Graham Bond may have been the first "rock" musician to record with a Mellotron, beginning
in 1965. A year later The Beatles used it prominently on their ground breaking single "Strawberry Fields Forever"
(recorded November-December 1966). However, it was Mike Pinder of the Moody Blues who brought the Mellotron to
the fore of popular music with the 1967 album Days of Future Passed in songs including "Nights in White Satin" and
"Tuesday Afternoon". Pinder made regular use of the Mellotron on the Moody Blues' studio albums from 1967 through
1971. Their 1972 album Seventh Sojourn employed the Chamberlin.

The Mellotron was also used by The Zombies ("Changes"), Manfred Mann ("Semi-Detatched Suburban Mr. Jones"), Lynyrd
Skynyrd ("Tuesday's Gone"), The Rolling Stones ("2000 Light Years from Home"), The Bee Gees ("World", "Every Christian
Lion-Hearted Man Will Show You"), Traffic ("House for Everyone", "Hole In My Shoe"), Pink Floyd ("A Saucerful of Secrets",
"Julia Dream", "Sysyphus" and "Atom Heart Mother"), Procol Harum ("Magdalene (My Regal Zonophone)"), The Left Banke's
"Myrah", Marvin Gaye's Mercy Mercy Me (The Ecology), David Bowie ("Space Oddity", where it was played by Rick Wakeman)
and others during the psychedelic era. The Kinks featured the instrument prominently in their recordings between 1967
and 1969, particularly on the 1968 album The Kinks are the Village Green Preservation Society.
John Paul Jones of Led Zeppelin used a Mellotron to play the recorder part (with flute tapes) on Stairway to Heaven live.
His Mellotron is pictured at his left underneath a Hohner Clavinet.
John Paul Jones of Led Zeppelin used a Mellotron to play the recorder part (with flute tapes) on Stairway to Heaven live.
His Mellotron is pictured at his left underneath a Hohner Clavinet.

The Mellotron was widely used to provide backing keyboard accompaniment by many of the progressive rock groups of
the 1970s and alongside the venerable Hammond organ it was crucial to shaping the sound of the genre. It features on
albums such as Once Again by Barclay James Harvest, In the Court of the Crimson King by King Crimson, Diamond Dogs
by David Bowie, 2112 by Rush, I Robot by The Alan Parsons Project, Fragile and Close To The Edge by Yes, and Nursery
Cryme, Genesis Live, Foxtrot, Selling England By The Pound, The Lamb Lies Down on Broadway, A Trick of The Tail,
Wind And Wuthering and Seconds Out by Genesis. This band also achieved the greatest peaks of darkness with this
instrument in the songs The Fountain of Salmacis and Blood on the Rooftops. Especially haunting was the chorus used
on "Los Endos" on A Trick of the Tail, and the famous introduction to Watcher of the Skies.

Led Zeppelin used a Mellotron to recreate the recorder arrangement for live performances of "Stairway to Heaven",
and is featured prominently on "The Rain Song" from Houses of the Holy. It was also used extensively by pioneering
German electronic band Tangerine Dream through their prime, including solo work by Edgar Froese. The Tangerine
Dream albums Phaedra, Rubycon, Ricochet, and Encore as well as Froese's Epsilon in Malaysian Pale provide excellent
examples of Mellotron playing. Another example of mellotron sounds can be heard on Immediate Curtain, played by
former Soft Machine-percussionist Robert Wyatt on the first album of his second band Matching Mole.

German progressive rock band Amon Düül II used Mellotrons on their 1972 album Wolf City.

The advent of cheaper and more reliable polysynths and preset 'string machines' saw the Mellotron's popularity wane
by the end of the 1970s. Following the impact of punk, the Mellotron tended to be viewed as a relic of a pompous era.
By 1980, Switzerland's progressive rock band Flame Dream used the Mellotron on all 6 of their Vertigo, Phonogram
albums; and its status had diminished to the extent that Captain Beefheart was able to reappropriate it almost as an
archaic "found instrument". One of the few UK post-punk bands to utilize its sounds were Orchestral Manoeuvres in
the Dark, who featured it heavily on their platinum-selling Architecture & Morality album (1981).

The Mellotron experienced a revival of sorts in the 1990s. A variety of bands began using the instrument, including You
Am I, Marillion, The Smashing Pumpkins, Oasis, Barenaked Ladies, Nine Inch Nails, Muse, Grandaddy, Tom Waits,
Radiohead, Porcupine Tree, Opeth, and Waterclime. On Porcupine Tree's 2005 album Deadwing, track six is titled
"Mellotron Scratch" and includes lyrics about the sound of a Mellotron causing a woman to cry. In late '89/'90, R.E.M.
laid down those mysterious sounding cello parts that are so prevalent in the cut "Losing My Religion", using the Mellotron.

Woolly Wolstenholme of Barclay James Harvest still gigs and records with a Mellotron, with both his own band
Maestoso and with John Lees' Barclay James Harvest. Although he now plays an M400 rather than the M300 he is most
famous for, his Maestoso albums Grim (2005) and One Drop In A Dry World (2004) feature numerous examples of his
use of the M300 string sound that became his trademark.

The Red Hot Chili Peppers have been known to use the Mellotron, first on Blood Sugar Sex Magik. It was played by
Brendan O'Brien on the tracks "Breaking the Girl" and "Sir Psycho Sexy". Though it is unconfirmed whether or not it is
a Mellotron, a similar flute sound to that of "Breaking the Girl" can be heard on the track "Snow ((Hey Oh))" from the
2006 album Stadium Arcadium. John Frusciante, the guitarist for the band, also plays the instrument, most notably
on 1999's Californication album, on the song of the same name. He also uses the mellotron prolifically on his solo
album "Shadows Collide With People".

The Strokes' 2006 album, First Impressions of Earth, features a Mellotron solo on the track "Ask Me Anything". It is
played live by Nick Valensi, the lead guitarist.

John Medeski of Medeski Martin and Wood has toured extensively with a Mellotron since December 1997. He is
frequently known to manipulate the tape speed by reaching inside the instrument to produce warped and sometimes
unsettling sounds.

Trent Reznor of Nine Inch Nails borrowed John Lennon's home Mellotron - a MkII in black finish, which he has used
in several albums including Marilyn Manson's Antichrist Superstar and the Nine Inch Nails album The Downward Spiral.

D.S. Poe, Keyboardist and Bassist for MorissonPoe, plays Mellotron on Pearl Necklace, which was featured on Xbox
360's Perfect Dark Zero video game.

Matt Thiessen of Relient K tracked Mellotron on the 11 minute epic "Deathbed" from the album Five Score And Seven
Years Ago.

Rush, after moving away from keyboards in the 1980s and 90s with two synth-less records (Vapor Trails and Feedback),
brought the Mellotron in for their 2007 release Snakes & Arrows.