It is hard to believe today that there was once a time when there were just two synthesiser manufacturers: Moog and ARP (three, if you count UK manufacturer EMS) and each one had just a handful of products. Moog and ARP were constantly battling it out, each one trying to get the upper hand in this new and exciting market in the late '60s / early '70s.

Both companies started off with big modular synths and scaled down... Moog with their MiniMoog and ARP with their Odyssey. However, even though these two synths were considerably easier to use than their wall-to-wall predecessors, you have to remember that at the time, analogue synthesis was hi-tech rocket science that most people couldn't get their heads around.

To overcome this and to make synths more acceptable and portable (especially to the large organ market of the time), ARP brought out their 'Soloist' synth (right) in 1972. This was the first synth to offer preset sounds and these were selected using organ-like 'tabs' underneath the keyboard. Some rudimentary controls were also included that allowed you to customise a sound to your own requirements.

This concept was refined into the far more stylish 'Pro-Soloist' (top left).

The Pro-Soloist was a single oscillator, monophonic synth and so had limited creative possibilities compared with the Odyssey and the MiniMoog. However, it was a popular synth for live work (as you can imagine with those instant presets) and found favour with a wide range of keyboard players that included Herbie Hancock, Billy Preston, The Enid (who used the Pro-Soloist to great effect in their synthesised orchestrations), Vangelis and also Tony Banks of Genesis who first introduced the synth to the band on the album 'Selling England By The Pound'... in fact, you can begin to understand the appeal of the Pro-Soloist when you listen to the lengthy keyboard solo in 'The Cinema Show' where Banks flicks from preset to preset - such a performance would have been impossible on any other synth of the time, especially live. The Pro-Soloist remained a mainstay of the Genesis sound for many years despite Banks acquiring an ARP 2600 and a host of other synths.

ARP subsequently upgraded the Pro-Soloist concept with the Pro-DGX and the Pro-DGXII but these were simply variations on the the original theme (and many claim that they didn't sound as good due to revisions in the filter circuitry).

Samples donated by 'Stephan from Holland'.