"Love Action (I Believe in Love)" is a song by the British synthpop group The Human League, released as a single in the UK in July 1981. It became the band's first Top 10 success, peaking at number three in the UK Singles Chart. The song was written jointly by lead singer Philip Oakey and keyboard player Ian Burden. It features lead vocal by Oakey, female backing vocals by Susanne Sulley and Joanne Catherall, and analogue synthesizers by Jo Callis, Philip Adrian Wright and Ian Burden. Drum machines, sequencing and programming were provided by producer Martin Rushent and his then engineer and programmer David M. Allen. One of the most notable synth sounds on the recording makes use of the pitch-to-voltage converter and envelope shaper on the Roland System 700 modular synth. Jo Callis' guitar strumming was fed into the synth and used to shape and trigger the sounds, producing an unusual choppy, strumming synth patch. Some copies of the single were mispressed, with Orchestral Manoeuvres in the Dark's "Souvenir" as the A-side.[citation needed]