The music icon revealed the news ahead of Sunday's headline performance.
The songwriter once described as "Scotland's answer to Ray Charles" has died.
Glasgow-born Jim Diamond who was once described as "Scotland's answer to Ray Charles" has died aged 64.
The singer-songwriter first achieved fame with the band Ph.D alongside Tony Hymas and Simon Phillips, with the 1982 hit 'I Won't Let You Down'.
Once the band split, Jim signed with A&M Records and had a number one hit with 'I Should Have Known Better' and his song 'Hi-Ho Silver' was used as the theme tune for the ITV series 'Boon'.
In 2011, he released an album of soul covers with fellow Scottish musicians including Wet Wet Wet drummer Tommy Cunningham and Greg Kane of Hue & Cry.
Jim passed away at his home in London on Thursday 8th October leaving behind his wife Chrissy and children Sara and Lawrence.
His family said they are "deeply shocked by his sudden death".
Picture Credit: jimdiamond.squarespace.com