I read a story that Joe Perry, when he ditched Aerosmith back in the early 80's, was either asked to join or wanted to record with Alice Cooper.
Given the time frame of such a team-up (early 80's), I wonder how Joe's style and playing would have impacted Alice's more "new-wave" sound he was experimenting with at the time. Would Joe keep Alice in a more rocking direction or would he just went along for the ride and allow his guitar playing take a back-seat to synthesisers?
There was also a brief period in time when Zakk Wylde "auditioned" for Guns n' Roses. I can't remember the exact time line of that happening, but I'm pretty sure Slash was still in the band and they were looking for a 2nd guitarist to replace Izzy Stradlin. I'm not sure that Guns n' Roses' style would benefit from a twin-axe attack like Judas Priest, but hearing those 2 guys playing together would certainly have been interesting.
_________________
I used to be with it, but then they changed what "it" was. Now what I'm with isn't it, and what's it seems weird and scary to me, and it'll happen to you, too.