"Ian was the sweetest, kindest, loving husband I could ever have wished for and I take comfort that he is resting now up there in his very own piece of Blue Blue Sky," she wrote in reference to the Alan Parsons song Bairnson played on.
"Although Ian has left us, his musical legacy stays with us and will continue to delight and brighten our lives, as it did his, forever," she added.
Bairnson came from Lerwick in Scotland's Shetland Islands and was a member of The Alan Parsons Project between 1975 and 1990, after working with the band Pilot alongside former Bay City Rollers musicians David Paton and Billy Lyall and contributing to their 1974 hit song, Magic.
He went on to work with Kate Bush and played on her first four albums, including playing the solo on Wuthering Heights from 1978 debut, The Kick Inside. During Bairnson's work with Bucks Fizz in the early '80s he co-wrote their top 20 hits If You Can't Stand the Heat Run For Your Life.
Bairnson's prolific session career saw him play live with Eric Clapton and Sting, while his recording resume featured over 100 albums from artists including Neil Diamond, Joe Cocker, Yvonne Keeley and Mick Fleetwood.