Just look what happened when Scottish singing sensation Susan Boyle finally had the opportunity to sing alongside West End legend Elaine Paige - that's right, it was an epic bust.
Paige laid down vocals for a duet with Boyle only to receive a diss that diva's of her magnitude are rarely afforded: the track was dropped from Boyle album.
Paige had recorded her part of I Know Him So Well from the musical Chess - until Boyle's management unceremoniously pulled the plug.
Paige, 62, was mystified - and, to be honest, miffed. "I did put my part of the duet down," the star told the press. "But they didn't do it. I don't know or understand quite why. It's a difficult scenario with Susan. The record company are very protective of her. They've made a choice not to sing with me. So that's fine by me."
Really? You're not bothered even a little bit?
"Susan has her career and I have mine," Paige continued. "We don't need to sing with each other to have a career."
Perhaps the reason for the frostiness shown her by Boyle's management could have something to do with Paige's comments in January at the South Bank Awards.
Paige was quoted as saying: "Susan was like a virus really that spread across the world in a nanosecond."
"She has done terribly well to be a major star overnight with YouTube."