Duncan Mackay was born in Leeds (UK) on 26 July 1950. After earning a music scholarship in Shrewsbury Public School, he finished his studies in 1967 obtaining his L.T.C.L. and L.R.S.M diplomas in violin. Soon was invited to join the Sergio Mendez band. In 1975 he joined Steve Harley and Cockney Rebel. After leaving Cockney Rebel in 1977, he joined 10CC until 1981. Meanwhile, he recorded music with other artists as well.
For Kate, Mackay played electric piano on the songs Moving and L'Amour Looks Something Like You; clavinet on the song Kite; organ on the songs Kite, Wuthering Heights, and James And The Cold Gun; Fender Rhodes on the songs Symphony In Blue, In Search Of Peter Pan, and Don't Push Your Foot On The Heartbrake; synthesizer on the songs Strange Phenomena, Wow, Coffee Homeground, and Hammer Horror; and Fairlight on the songs All We Ever Look For and Army Dreamers. He also played on Camel's 1981 album 'Nude', and Budgie's 1982 album, 'Deliver Us from Evil'.
Meanwhile, Duncan Mackay also recorded solo albums, starting with 'Chimera' in 1974 and continuing throughout the 1980's. In 2004, he completed an album with South African singer/composer Greg McEwan-Kocovaos, entitled 'The First Time'.