Mr. Ray Purchase asks: What Happened to the Analogue Synthesiser?

In the early 70s, as a youngster ....

I became aware of the music synthesiser. To me the word “synthesiser” conjured up a vivid impression of the sound and look of the instrument, and still does. I imagined that synthesisers were so expensive, futuristic and exotic that they probably had to be borrowed from government research establishments. The idea that they could produce an infinite variety of sounds enabling the lucky user to play effectively any musical instrument was exciting beyond belief. Gradually I began to understand how they worked and that they were attainable by mere mortals, and as a teenager I experimented with analogue Moog-style instruments myself. Later, computerised instruments like the Fairlight CMI became the objects I lusted after, and now three decades on, like everyone else I can realise any instrument I like using free software on a standard PC.

But the amazing thing is that all this time later it is the very first synthesiser sounds that have stood the test of time. Later synthesisers that began to sound like 'real' instruments or that introduced 'innovative' digital architectures (like the Yamaha DX synths) have either faded into a general impression of naffness, or into obscurity as they didn't stand out enough to be noticed. The original Moog-style sounds are still there, still sound startling, and can be modelled perfectly using computers.

How it Works

What goes into making these beautiful sounds? It's very simple. The basic building blocks are modules that feature inputs and outputs for signals, plus inputs for control, and it is the way that these control inputs can be modulated by the outputs of other modules that gives the synthesiser its power and flexibility. The original synthesisers were all analogue and the controls and signals were voltages, but these days they can be realised entirely in software.

A basic synthesiser 'patch' could typically be a repeating audio waveform generator known as an oscillator feeding a frequency-selective filter, in turn feeding into an amplitude modulator. These three modules satisfy the most basic requirements for synthesising a monophonic musical instrument or voice: an excitation waveform, a means of changing its pitch and timbre and a means of changing its amplitude. To go N note polyphonic, the modules are simply duplicated N times, but in the early days synthesisers were strictly monophonic, which may have had something to do with the minimalism and beauty of many of the tracks featuring them in the 70s.


To play with an analogue monosynth is to be immediately struck by the familiarity of the sounds. A couple of basic oscillator waveforms are available, sawtooth and square being typical - the names are descriptions of the shape of the voltage-versus-time waveform. Sawtooth is the basis of many a 'brass' or lead type sound, while square wave sounds more 'hollow' but can be modulated by dynamically changing the pulse width to produce a very attractive effect. Mix the output of two oscillators at slightly different frequencies and a fabulous 'beating' occurs that is the hallmark of analogue 'synth'. Or mix them almost an octave apart for an even more bombastic sound. The oscillators' pitch is usually controlled by the keyboard but can be further modulated by other oscillators and modules. The pitch transitions between notes can be set up to slide with a portamento effect if so desired.

 The filter module acts effectively as a treble boost or cut that can track the oscillators' pitch, or it can be set up to have a frequency-selective peak or resonance. When swept dynamically (manually by turning a knob or automatically by a low frequency oscillator or ADSR Attack-Decay-Sustain-Release generator triggered by a key press for example), the audible effect is more complex than might be expected, and very characteristic of the analogue sound.

 The final block is usually the amplitude modulator that again can be driven automatically in response to a key press using an ADSR generator to give a percussive note effect using short attack and moderate decay, or a smoother attack, long decay etc. Mixing in the output of a low frequency oscillator (LFO) with the control signal gives a tremolo effect – it's that simple. Completely modular synths allow any combination of module outputs to modulate any other modules' control inputs via a real or virtual 'patch panel', but many synths only allow a selection of the more conventional permutations.

 Unique Sounds

To me, the sounds produced by this simple technology were, and are, startling, delicate, unique, weird, and not merely substitutes for conventional musical instruments, but beautiful sounds in their own right (although it was always an interesting game to try to simulate an acoustic instrument using an analogue synthesiser). Unlike natural acoustic instruments, the basic analogue synthesiser is without 'formants' i.e. without fixed frequency peaks that do not track the pitch, and even if it is set up to have them they will likely be very simple. Immediately this makes the synthesiser distinct from any acoustic instrument. At the same time, its sound is more complex than an electronic organ, and can be given many dimensions of modulation that a skilled musician can use to make the notes more expressive. However, unlike a conventional instrument, these forms of modulation are generally completely isolated from one another e.g. bending the pitch does not change the amplitude or timbre at all, which gives the sounds a peculiar perfection. Not only did the early synthesisers produce unique sounds, but lent themselves to being controlled by digital sequencers, which in turn led to music based on repeating patterns, again with a strange artificial perfection and driving constancy.

 It was always common to supplement the synthesiser with conventional time delay-based effects (echo, reverberation, chorus) and to use it as part of a mixture of instruments with voice, acoustic drums, electric guitar and so on. The contrast between the purely electronic and the acoustic/electromechanical was often vivid. I think that were and are people who 'got' the unique beauty of the synthesiser, and there were others who used it as a convenient way to pad out their musical productions and nothing more.

 Top tracks

Here is a selection of recordings that I think were created by people who understood the unique beauty of the analogue synthesiser:

Definitive Gaze – Magazine, 1978

A conventional New Wave lineup but transformed by the addition of lead and string synths to create a vibrant, shimmering track. I can't help but wonder why many bands are purists and don't use variations on this combination.

Dignity of Labour Part 3 – Human League, 1979

Hard core analogue synth sounds based around arpeggiated PWM(?), with shimmering, tinkly, swirly stuff around it. Simple (but not implying that I could do it!) and made by a few lads from Sheffield but it sounds other-worldly, meaningful and even moving.

Equinoxe Part 1– Jean Michel Jarre, 1978

Shimmering string synth with echo over slowly modulating bass note and simple melodies with notes that rise upwards constantly until the end where they begin swooping downwards. To have created something so beautiful with a few analogue synths and tape recorders... what did it feel like?

Blade Runner – Vangelis, 1982

Lots of reverb, brassy filter sweeps, string synths, tinkly chimes and notes that die away swooping downwards into the reverb.

Persuaders Theme – John Barry, 1971

Based on a bass synth sound that almost achieved the 'brown note' the first time I heard it as a kid, so exciting did I find it.

Frankenstein – Edgar Winter Group, 1973

Unique, exuberant rock track around a portamento lead synth line that positively 'honks'.

Are Friends Electric – Gary Numan, 1979

Constant steady tempo, a lot of open space, repeating lead synth line, beating oscillators aplenty, and great 'hooks'. Drums, bass and voice mixed with synth is a killer combination. (And a special mention for the Sugababes superb track based on samples of this song, Freak Like Me).

Black Cherry (album) – Goldfrapp, 2003

Analogue (style) tour de force with surely some of the heaviest electronic bass underpinning of any songs and lovely swooping oscillators/filters/twiddly stuff over the top. Very nice voice, too.

Star Cycle – Jeff Beck, 1980

Also known as the theme from the Tube, starts with a trilled electric guitar punctuated with a swept sync oscillator sound, then goes into a repeating synth sequence changing key periodically, with guitar, bass and drums for the entire track. I love that synth sequence for the sound itself, its simplicity and constancy, and the resulting complexity of the interplay with the drums and other instruments.

Kelly Watch the Stars – Air, 1998

Air know how the analogue bass, string synth and vocoder evoke a certain cheesy glamour and sophistication from the 1970s that seems very refreshing today.

Lucid Dreams – Franz Ferdinand, 2008

So far so conventional (and perfectly fine) until at about 4'40 the song goes off into a pure analogue-style stereo synthesiser workout that sounds like thunder on big speakers.

Who Are You – The Who, 1978

Thrilling rock track based around a sequenced 'squelchy' swept filter synth sound that runs through the whole song.

I Hear You Now – Jon and Vangelis, 1979

Beautiful electronic sounds and voice over a simple synth arpeggio. As with the Blade Runner theme it contains reverb'ed notes that tail off in pitch – did I mention I love that sound?

A Rainbow in Curved Air – Terry Riley, 1967

An 'ambient' piece using layers of sequenced oscillators and rapid twiddling over the top with more organ/oscillator.

The Grid from Koyaanisqatsi – Philip Glass, 1982

A mixture of acoustic instruments, voices and manually-played synthesisers. The rapid bass synth part that continues underneath much of the piece contrasts excitingly and weirdly with the classical sound of the voices and other instruments.