Early analog synthesizers such as the Pro One left an indelible mark on synthesizer design. In the 1970s and early 1980s, these instruments offered a way forward for composers and musicians who felt stifled by the rigour of early electronic music techniques. They promised new timbres and uninhibited methods of control and ultimately set into motion the foundations of synthesis practice that would follow into the modern era. The Pro One stands as among one of Sequential Circuits’ most commercially successful instruments, primarily on account of its comparatively affordable price tag. Notable groups to have used it include Depeche Mode, New Order, Prince, Soft Cell, and Vince Clarke. More recently, the Toronto-based rock quartet Metric feature this instrument both on recordings and in live performances.