John Travolta & Olivia Newton-John

John Travolta and Olivia Newton-John came together for the 1978 film 'Grease,' where their on-screen chemistry carried over into the recording studio. Travolta, primarily an actor at the time, insisted on singing his own parts, while Newton-John brought her established vocal presence to tracks like 'You're The One That I Want' and 'Hopelessly Devoted.' The soundtrack became a massive success, anchored by those singles and others such as 'Beauty School Dropout' and 'Take A Chance.'

Their collaboration was essentially a one-off for the film, though they did reunite for the 1983 movie 'Two of a Kind,' which produced the song 'Twist Of Fate.' The 'Grease' soundtrack remains their defining work together, a collection of songs that captured the late-70s moment and has stayed in circulation ever since.