Following the release of "I Wrote a Simple Song" on A&M, Preston's solo career peaked at this time, beginning with 1972's "Outa-Space", an instrumental track that further popularized the sound of the clavinet in funk music. The song reached number 2 on the US "Billboard" Hot 100 and topped "Billboard"'s R&B chart, before going on to win the Grammy Award for Best Pop Instrumental Performance. "Outa-Space" sold over 1 million copies in America, and was awarded a gold disc by the RIAA in June 1972. Later that year, Preston contributed the title song to the hit blaxploitation film "Slaughter" starring Jim Brown.