The Fairlight CMI (Computer Musical Instrument), introduced in 1979, was one of the first commercial digital sampling synthesisers. Expensive and revolutionary, it shaped the sound of the 1980s - used by artists such as Peter Gabriel, Kate Bush and many others - and its Page R sequencer pioneered pattern-based composition. Arturia's CMI V recreates the instrument and its synthesis methods, including sampling and additive synthesis.
Additive synthesis
Every sound can be described as a set of sine waves - harmonics - at different frequencies and levels. Additive synthesis builds sound by controlling those harmonics directly. Where subtractive synthesis starts with a rich wave and removes harmonics, additive starts with nothing and adds them.
- Harmonic partials at whole-number multiples of the fundamental give pitched tones.
- The balance of harmonics decides the timbre: strong odd harmonics sound hollow, like a square wave; all harmonics falling away evenly sound bright, like a sawtooth.
- Movement comes from changing the levels of harmonics over time.
Evolving timbres
The CMI's approach to additive synthesis lets you shape harmonic content across the duration of a sound, so the timbre evolves - bright at the start and mellowing, or slowly blooming. This is how real instruments behave: their harmonics change after a note begins.
Spectral and waveform tools
CMI V offers tools to draw and edit waveforms, build sounds from harmonic content, and create evolving spectra - alongside its sampling engine. Explore each and compare how the same idea sounds when made with different methods.
Sampling
The CMI was a sampler at heart. Its early sampling, at modest bit depths and sample rates, had a distinctive gritty, characterful sound - famous orchestral hits and choirs among them. CMI V lets you sample and process your own sounds in the same spirit.
Page R
The Page R sequencer let musicians build music from patterns on a grid - an ancestor of the step sequencers and pattern-based workflows in modern DAWs and grooveboxes. Programming a pattern in CMI V's sequencer is a good way to understand where modern beat-making workflows came from.
Additive elsewhere
Additive synthesis also appears in Pigments' harmonic engine and in other modern synths. Once you understand partials, you can work in any of them.
Do this now
- In CMI V, build a tone by adding harmonics one by one and listen to how each changes the timbre.
- Make a sound whose harmonics change over its duration - bright attack, darker sustain.
- Sample a short sound of your own into CMI V and play it across the keyboard.
- Program a pattern in the CMI V sequencer.