Ever had a song so unsettling even your closest collaborators refused to touch it? That’s what happened to Neil Young with 1974’s "Revolution Blues." Inspired by the Manson murders, it adopts Charles Manson’s voice to lay bare 1960s Hollywood’s dark underbelly, with visceral lyrics like “I hate them worse than lepers, and I’ll kill them in their cars.” CSNY bandmates (Crosby included) were spooked—they refused to share the stage, and Crosby still disliked it in 2015. This rift pushed Young toward Crazy Horse. What’s the most unsettling song you’ve ever encountered?