Brad Paisley to Black Flag in only 3 steps? And it involves William Shatner? WTF?
Shit, I can do that. Please tell me you are joking. Henry Rollins did "I can't get behind that" on Shatner's Has Been, which features the closing track "Real"(which is actually right after Rollins' song), that Brady Paisley sings on. So please tell me you are joking, because that one is super easy and obvious.*
*I should probably add that I am madly madly madly in love with both Henry Rollins and William Shatner
ETA:
ICP to Amanda Palmer in 5 steps
The Knife to Amanda Palmer in 13 steps(which makes me lol because it includes A Perfect Circle, and they have an album called 13th Step)
Black Sabbath to Amanda Palmer in 11 steps
Slint to Amanda Palmer in 9 steps.