For all the empathetic message-making in Curtis Mayfield’s music through the ’70s, the Chicago soul great’s perceptive lyrics and yearning falsetto always made the political seem acutely personal. On his fifth album, Sweet Exorcist, Mayfield demonstrates that talent most powerfully in the title track, a passionate plea for spiritual and emotional liberation that makes cunning use of a certain horror-movie title; “Power to the People” is an incredibly funky defense of America’s most vulnerable in a time of strife.