Musser Maestro Marimba Metron. Clair Omar Musser. USA, 1949

Musser’s ‘Maestro Marimba Metron’

“Musser Maestro Marimba Metron” or  “Rhythm Machine” was an early ancestor of the drum machine invented by marimba virtuoso and band leader Clair Omar Musser sometime after 1949. The instrument was  an analogue percussion sequencer designed to accompany Musser’s marimba performances and to teach rhythm to his students at Northwestern University and in his music room at Studio City, California.

The Rhythm machine was a hybrid electronic and electro-acoustic instrument built into an art-deco styled wooden box 18″ wide, 34″ deep, 32″ tall with a top control panel of switches, buttons and dials. The sound was generated using vacuum tube oscillators plus a set of ‘real’ cymbals that were struck with an electro-magnetic solenoid.


The Marimba Metron was able to re-play 13 electronically generated “tempi figures” – rhythmic accompaniments – such as the bolero, waltz, rhumba, cha-cha, tango, samba, and beguine. In addition to the pre-set loops, percussion sounds could be activated using push-button controls. Sounds included  bass drum, tom-toms, temple blocks, woodblock, claves, and maracas sounds, along with the two real cymbals struck by the electronic solenoid.

Clair Omar Musser (1901–1998) Biographical notes

was a marimba virtuoso, a conductor and promoter of marimba orchestras, a composer, a teacher, a designer of keyboard percussion instruments, an inventor, and an engineer for Hughes Aircraft. Musser was born in Pennsylvania and began to study the xylophone in the 5th grade. Upon witnessing a performance of Teddy Brown playing marimba with the Earl Fuller’s Rector Novelty Orchestra, Musser was inspired to study with Brown’s former teacher, Philip Rosenweig. Musser soon became recognized as a virtuoso in his own right, performing as a soloist, with orchestras, and in an early Warner Bros. Vitaphone film.


‘Movement MCS drum computer’ John Dickenson & Dave Goodway, United Kingdom, 1981

The 1983 version ‘Movement MCS drum computer’ (image: Matrixsynth

The Drum Computer (or Percussion Computer) from Movement Computer Systems is a very rare British made drum machine made circa 1981 – the era where drum machines were moving from preset patterns to programmable instruments. It is estimated that only 30 or so units were produced. The instrument combined analog synthesized drum sounds (Simmons style) and digital 8-bit sampled drum sounds (LinnDrum style). There were seven voice cards, each with two drum voices giving a total of 14 (preset) drum voices. Each drum voice could be switched between either the analog (synth) or digital (sample) mode and has its own Volume and Pitch-Sustain control knobs. The most prominent innovation was its programmable computer-like interface which allowed graphic editing and sequencing of patterns (but not sounds) via a monochrome display. The instrument was equipped with numerous outputs for audio and trigger input/output per voice and data storage bus to a cassette tape.

The MCS Mk2 c1983

Two models are known to exist: the MK1: a two-piece unit in which the monitor was separate from the rest of the machine, and the MK2 (released in 1983) which integrated the CRT monitor and had an orange (or black) case. In 1984, the MIDI specification was added to the MK2, along with an additional 8-track sequencer, battery backed memory and a floppy disk drive.

Well known users of the MCS include David Stewart of the Eurythmics (on tracks such as “Sweet Dreams”), Phil Collins, The Thompson Twins, Human League, Thomas Dolby, Kajagoogoo, Japan, Willian Orbit, Chemical Brothers and Vince Clarke. Despite its innovative and versatile interface the MCS lost out to overwhelming competition from Linn, Simmons and Oberheim partly due to cost (approximately 1981 (MKI) and 1983 (MKII). Both retailed at £1999.00 ) and inferior sound quality and the MCS was discontinued around 1984.

“Movement was John Dickenson. He previously played keyboards with Greg Lake in a band called ‘Shy Limbs’ as well as many other groups. I met him shortly after he moved from Bournemouth to Somerset here in the UK and I started doing some engineering and session work in his new Movement Studios. We were working on the recording of his album which was called ‘Divided We Stand’ by King Harry (which was John plus 2 of his old friends plus various local musicians contributing). This was released in 1977 just as the punk movement took off here in the UK which virtually killed the album stone dead. Timing eh?
A friend of mine also did a lot of technical work for John. His name was Dave Goodway and he was the guy who designed the Movement Drum Computer and wrote all the software for it. I’m not sure of the exact date of the development but Annie Lennox and Dave Stewart were spending time with John after the breakup of the Tourists and before the Eurythmics came to fame. That would put it during 1980. It was about the time that the Linn Drum was first developed. If I recall, several big stars of the day had Movement drum computers – Eurythmics, Thompson Twins and Pete Townsend spring to mind and I think Pink Floyd also used them. In fact most people had several as they were quite unreliable because the technology was still very new. I had one in my own studio for a few months which belonged to the Thompson Twins while it waited for a new display.
Models for sale were generally finished in orange but some of them had black cases and some others had wooden cases. I can’t remember if the different case types denoted any specification changes or whether it was just customer choice. I don’t know how many units were produced but it would have been a relatively small number.”
1David Crabb, Movement employee, quoted from ‘Studio Electronics’ website:


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    David Crabb, Movement employee, quoted from ‘Studio Electronics’ website:

Chamberlin ‘Rhythmate’, Harry Chamberlin, USA,1947

Chamberlin Rhythmate
Chamberlin Rhythmate

Created in 1949, The ‘ Rhythmate’ was one of the first electronic drum machines ever produced. The instrument was designed and built (probably only ten machines were ever produced) by Harry Chamberlin in Upland, California. With the success of the Chamberlin keyboards in the 1960s Harry Chamberlin updated the drum machine – the Rhythmate model25/35/45 produced from 1960-1969 with 100 models sold.

Chamberlin Rhythmate
Control panel of the Chamberlin Rhythmate 1960’s model

The Rhythmate was a tape loop based drum machine designed to accompany an organ player. the instrument had 14 tape loops with a sliding head that allowed playback of different tracks on each piece of tape, or a blending between them. It contained a volume and a pitch/speed control and also had a separate amplifier with bass, treble, and volume controls, and an input jack for a guitar, microphone or other instrument. The tape loops were of real acoustic jazz drum kits playing different style beats, with some additions to tracks such as bongos, clave, castanets, etc. The Rhythmate has a built-in amplifier and 12″ speaker.

In 1951, Harry Chamberlin used his idea of magnetic tape playback to create the Chamberlin Model 200 keyboard. The Model 300/350, 400, 500 and 600/660 models followed.

Chamberlin Rhythmate
Inside the Chamberlin Rhythmate showing amplifier 10″ speaker and tape loops