Mackay was later head-hunted by EMI Australia, which initially employed him as a Recording Engineer but soon promoted him to "Head of Artists and Repertoire".
He also diversified into the medium of television, arranging and producing themes such as Coca-Cola's "I'd Like To Teach The World To Sing" as well as scores for BBC TV shows Auf Wiedersehen, Pet, Carla Lane's Bread, Streets Apart and As Time Goes By.
The Auf Wiedersehen, Pet project notably generated a hit single, "That's Livin' Alright", by Joe Fagin, which won Mackay an Ivor Novello Award and a BAFTA nomination.
The World Starts Tonight (1977) is the debut studio album by Welsh singer Bonnie Tyler, released in February 1977 by RCA Records.
In 1990, Mackay and Jon English co-wrote a concept album, Paris, which has since been staged as a rock musical in Australia and elsewhere several times beginning in 2003.