Roland MC-4 Microcomposer

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.[4] Note, however, that Middle C as the value 24 is relative to whatever settings one has set on the synthesizer to be sequenced.

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. To set the time values, one must first set a time base, typically 120. This means that a quarter note = 120, a sixteenth note = 30, an eighth note = 60, etc. Esoteric timings can be programmed by entering any number against whatever time base is entered. 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.[7]

Alternatively, the MC-4 can record live playing from a monophonic keyboard.

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).

After a sequence has been programmed it must be saved, as the memory is volatile: when the power is switched off, memory contents are lost. An optional digital cassette recorder, the Roland MTR-100 was available for this purpose. The owners manual shows that a programmed sequence could also be saved to a standard cassette deck.[8] This is good news as the MTR-100 is quite rare to find.

When saving or loading programs, the CMT (Cassette Memory Transfer) mode must be selected. Programs are saved using program numbers for identification.[9]

The Roland MTR-100 was a digital tape recorder used for storing sequence programmes for the Roland MC-4 Microcomposer. It was offered as an optional accessory for faster data transfer than a standard audio cassette player.[11] When using a Roland MTR-100, the Roland MC-4 Microcomposer needed to be fitted with the additional memory option known as the OM-4. The MTR-100 used digital computer cassettes, Roland endorsed the use of TEAC Computer Tape CT-300 or Maxell Data Cassette Tape CT-300 or M-90.[12]

Vince Clarke began using the MC-4 on Yazoo's debut album Upstairs at Eric's in 1982. After a good friend noticed that his later albums had changed in sound, 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. Clarke believed at the time that MIDI had timing problems due to data bottlenecks, and CV had much tighter timing. The whole sound of 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.[18] Clarke was later quoted as saying that he bullied the spares department at Roland UK to supply the micro-cassettes needed for data transfer and later described the MC-4 as being "a pig to program but well worth it".

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 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 MPC60II.[19] Before the tour Clarke's collection of MC-4 sequencers were ‘road hardened’ by having the chips removed from their sockets and soldered directly to the circuit boards.[18]

Eight MC-4 sequencers were obtained for the tour as back up units, but they were not needed.[19]