You're The One That I Want by John Farrar

John Clifford Farrar ( FAR-ər; born 8 November 1946) is an Australian music producer, songwriter, arranger, singer, and guitarist. As a musician, Farrar is a former member of several rock and roll groups including The Mustangs (1963–64), The Strangers (1964–70), Marvin, Welch & Farrar (1970–73), and The Shadows (1973–76). In 1980, he released a solo eponymous album. As a songwriter and producer, he worked with Olivia Newton-John from 1971 to 1989. He wrote her U.S. number-one hit singles: "Have You Never Been Mellow" (1975), "You're the One That I Want" (1978 duet with John Travolta), "Hopelessly Devoted to You" (1978), and "Magic" (1980). He also produced the majority of her recorded material during that time, including her number-one albums, If You Love Me, Let Me Know (1974), Have You Never Been Mellow (1975), and Olivia's Greatest Hits Vol. 2 (1982). He was a co-producer of the soundtrack for the film Grease (1978).

Farrar also produced Newton-John's first American number-one hit single, "I Honestly Love You", which was awarded the Grammy Award for Record of the Year in 1975. In 1969, Farrar married the Australian singer, Pat Carroll, who had been Newton-John's singing partner. In July 1970, Farrar and Carroll relocated to the United Kingdom and, since late 1975, they have resided in the United States. They are the parents of Sam Farrar, bassist of Phantom Planet and Maroon 5, and Max Farrar, a composer and producer whose work includes songs with Lewis Capaldi and The Script.