The Milwaukee Rep tackles one of country music’s most towering icons—and one of its most distinguished songbooks—in its Stackner Cabaret production of Ring of Fire: The Music of Johnny Cash. Richard Maltby, Jr. directs a production that features the Milwaukee Rep debuts of Trenna Barnes, Eddie Clendening, Jason Edwards, David Miles Keenan and Mark W. Winchester, who will since more than two dozen of the Man in Black’s signature songs, including “Folsom Prison Blues” and “I Walk the Line.”