It’s hard to imagine now, but there was a point when Johnny Cash was considered … uncool. Sure, he was always the Man in Black, but there was a long string of disposable albums of children’s music, gospel, Christmas songs and re-released material. Then along came the epically bearded rap and rock producer Rick Rubin (co-founder of label Def Jam), and thus was born one of the more fruitful — and unusual — musical collaborations of the 1990s. With stripped-down production, generally just Cash’s deep voice and a guitar, American Recordings launched the erstwhile country star past his Nashville fans into the mainstream. Covering songs by Danzig and Tom Waits, Cash showed he was as hip as anyone to anything different — as long as it was good. Cash and Rubin recorded four more American albums, the last released after Cash’s death.