Some unlikely/less likely band collaborations

Saga and Tangerine Dream aren't much unlikely, IMO.

One unlikely is Genesis lead by Phil Collins with the late Stormy Six 

Now if I could design a parallel world with one such collaboration in it, I'd have Peter Gabriel singing for Can. Even if I'd somehow have to integrate Genesis' other members, it may be worth it. 

Nice listing ... and it had my imagination running wild!

The one I thought about was Edgar Froese in his book, talking about David Bowie, when he realized that David was not as open to free form and feel, as it was originally thought, and at that point he apologized to David and said that the styles and music was too different to make it work. It's the longest chapter in Edgar's book, but it really says a lot more about his talent and how it works than David, who often "had to find his voice" in his lyrics per the producer quote in the book. I don't think that Edgar, through his years, ever really wondered about a wrong "note" even though his constant looks at the members sometimes suggest otherwise, but I think those were more cues than anything else.