The singers chatted to staff and patients at Maggie's Gartnavel, the second such base to be built in the city.
Pat and Greg Kane, who make up Hue and Cry, will star at the dinner to mark 10 years of the charity in Glasgow.
Pat said: "Having come to a Maggie's Centre gives a far greater emphasis to our performing at the gala dinner.
"I imagine coming to Maggie's would bring a sense of calm to anyone who had just been diagnosed with cancer.
"It is also a beautiful, stunning and striking building with an incredible atmosphere, and I am so glad we came to experience it first hand and to meet people who have been helped."
The gala dinner is at Duntreath Castle, Strath- blane on September 29.
Maggie's Glasgow Night Hike, of which the Evening Times is media partner, is on September 7.
It is a 10-mile fundraising walk around the city at night with exclusive access to buildings – such as The Riverside Museum, and The Art Club – where the walkers will find refreshments and entertainment.