Derek McArthur, 43, allegedly hit the Scottish singer and TV presenter with the music case at the Linen Bar on Pollokshaws Road, on January 22, last year.
Papers from the court claim he 37-year-old and “did strike her on the head with a guitar case or similar implement, to her injury”.
McArthur from Shawlands, pled not guilty through a lawyer’s letter and a trial date was set for August at Glasgow’s Justice of the Peace Court.
Michelle rose to fame in 2003 when she was crowned the winner of Pop Idol.
She is a newspaper columnist and joined the Loose Women panel as a guest panelist this year.