Roland MC-4 Microcomposer

The Roland MC-4 Microcomposer was an early microprocessor based music sequencer. It could be programmed using the ten key numeric keyboard or a synthesizer keyboard using the keyboards control voltage and gate outputs.

Information

This sequencer was released before the advent of MIDI, and viewed by some composers to have more perfect timing. The MC-4 has an output patchbay to the right of the control panel, allowing you to patch the MC-4 to a synthesizer using 3.5mm patch cords. There are four channels of outputs containing CV-1, CV-2, Gate and MPX (multiplex) to control four separate synthesizers. [page 1, Roland Microcomposer MC-4 Operation Manual] To the left of the output patchbay there are two switches and a control knob. The control knob alters the tempo of the sequencer. The first switch is for cycle mode (which allows the programmed sequence to repeat continuously until the sequencer is stopped), the second switch is for sync control. The MC-4 can be synced to other Roland equipment such as a drum machine or another MC-4 Microcomposer (offering eight separate channels of sequencing). [page 7, Roland Microcomposer MC-4 Operation Manual] .
In the centre of the control panel is the numeric keypad and enter button. To the right of this are two blue keys for advancing forward or backwards through a programmed sequence. Below the two advance keys there is another blue button used to tell the MC-4 that you have finished programming a single measure, for example a one bar phrase of notes. To the left of the numeric keypad are six more buttons. These buttons are used for editing the sequence that has been programmed; they include insert, delete, copy-transpose and repeat. The bottom two buttons are for moving the cursor on the screen from left to right. [page 8, Roland Microcomposer MC-4 Operation Manual] .
After a sequence has been programmed it needs to be saved, as when you switch the power off the memory is not stored. The MC-4 had an optional digital cassette recorder called the Roland MTR-100. The owners manual shows that a programmed sequence could also be saved to a standard stereo cassette deck or portable cassette recorder. This is good news as the MTR-100 is quite rare to find. [page 16, Roland Microcomposer MC-4 Operation Manual] .

When using the MC-4 for saving or loading programmes the CMT mode must be selected. CMT stands for cassette memory transfer. Programs were saved using program numbers for identification. [page 18, Roland Microcomposer MC-4 Operation Manual] .

Concepts in programming

The MC-4 can be programmed with the input of number values, using the control panel numeric keypad. When programming a sequence of notes into the MC-4 numerical values are entered. These correspond to the musical notes on a piano keyboard; Middle C would have the value of 24, increasing upwards for higher notes and downwards for lower notes. [page 1, Roland Microcomposer MC-4 Operation Manual] .

The second concept in programming the MC-4 are time values. The step time values determine the time interval between each musical note, or pitch. The third programming concept is the gate time. This gate time refers to the actual sounded value; whether the phrasing is legato, staccato, semi detached etc. [page 5, Roland Microcomposer MC-4 Operation Manual] .

yncing to MIDI

The MC-4 can be synched to MIDI using a clock to Din converter. When the MC-4 is powered up the display will show the TB (time base) default of 120. This is the number of clock pulses per bar; this was the standard before Din and MIDI clock came into being. If a sequence is programmed while the MC-4 is set to the default TB it will never sync correctly to Din or MIDI clock. To sync correctly the MC-4 TB needs to be set as 48/12/6, this sets the MC-4 for Din sync and defaults the step time to 16ths (12 clocks) and the gate length to 32nds (6 clocks).

Vince Clarke using the MC-4

After a good friend noticed that his later albums had changed in sound, Vince Clarke realised this had been due to his having changed from using a Roland MC-4 Microcomposer to using MIDI sequencers. So in 1991 he returned to using MC-4 sequencers for the recording of the Erasure album "Chorus" . After writing the tracks for the album, they were programmed into a BBC Micro computer, running a UMI sequencing program, to get the arrangements right. The UMI software sequencer was then synced to the MC-4 and all the parts were programmed into the MC-4. The whole theory behind programming with the MC-4 was better timing. Vince believed at the time that MIDI had timing problems due to data bottlenecks, and CV had much tighter timing. The whole sound of the "Chorus" is due to the MC-4 not being able to program chords; the limitation of only having four channels of sequencing also contributed. At this time he envisaged touring using the MC-4 sequencer. [SOS Magazine, December 1991]

After the recording of the "Chorus" album Erasure went on tour. He took on the challenge of using a Roland MC-4 as the main sequencer for the live shows. It was used to control various synthesizers live. The synthesizers controlled by the MC-4 included a Minimoog, Roland Juno 60, Sequential Circuits Prophet-5, Oberheim Xpander and a Roland Jupiter 8. For the drums the MC-4 was synced to an Akai MPC60. [Music Technology Magazine, August 1992] Before the tour Vince’s collection of MC-4 sequencers were ‘road hardened’ by having the chips removed from their sockets and soldered directly to the circuit boards. [SOS Magazine, December 1991]

Eight MC-4 sequencers were obtained for the tour as back up units, but they were not needed. [Music Technology Magazine, August 1992]

Roland MC-4 Additional Options

The Roland MC-4 Microcomposer was able to be used as a stand alone CV/Gate sequencer, but as the system advanced various additional options were made available for owners needing to use the MC-4 with new tasks and procedures. These involved things like memory expansion, cassette tape media and synthesizer interfaces. Below is a list of additional options that were made available by Roland. [Roland Microcomposer MC-4 Operation Manual and Roland OP-8 Operation Manual] .

* Roland MTR-100 (Digital Cassette Recorder)
* Roland OP-8 (CV/DCB Interface)
* Roland OP-8M (CV/MIDI Interface)
* Roland OM-4 (Optional Memory that converted an MC-4 into an MC-4B)

Notable users

* Vince Clarke
* The Human League
* John Foxx (The Garden Studio)
* Martin Rushent
* Kontour
* Landscape
* Aphex Twin
* Die Form

References