The ARP Pro-Soloist was one of the first commercially successful preset synthesizers and it was introduced by ARP Instruments, Inc. in 1972, when it replaced the similar ARP Soloist from 1970-1971. The ARP Pro-Soloist is a 30 preset monophonic analog synthesizer that had 30 preset sounds to choose from, including Flute, Bassoon, Brass, Fuzz Guitar, etc.. Other features include pitch, portamento, vibrato, growl and wow effects and it came with a 37 key-bed that had aftertouch sensitivity for volume, brilliance, vibrato, wow, and even pitch. It also had a basic filter (brilliance), envelope and LFO controls, allowing you to tweak some of the preset sounds, however it had no memory for those tweaks.

The ARP Pro-Soloist is a compact and basic mono synth that was best suited for leads and because of its onboard aftertouch feature, it's simply one of the most playable and expressive solo instruments Arp ever made. The ARP Pro-Soloist has been used by Quincy Jones, Donald Fagen (Steely Dan), Bernie Worrell (in Parliament Mothership Connection), Tangerine Dream, Tony Banks (Genesis), Vangelis, Styx, Herbie Hancock, Patrick Moraz, Gary Numan (on Telekon), Junie Morrison (Ohio Players), John Entwistle and Billy Preston to name just a few.