The Sequential Pro One is a crazy little mono synth. The synth was basically Sequential’s attempt to pack their legendary Prophet 5 poly synth into a compact, affordable, monophonic analogue synth. 

Vince Clark, founder of the bands Depeche Mode, Yazoo and The Assembly loved the Pro-One! The song “Don’t go” by Yazoo could be a demo song for the synthesizer, because so many sounds from the Pro-One are in it. The fact that we don’t see the synth in their music video, but instead a piano converted into an altar, shows the tribute Clark pays to his instrument. Another reason could be that bands at that time often masked brands on their synths or didn’t show the synth because they didn’t want to be a staged Advertisement for manufacturers.