Johnny Cash’s sideman

NASHVILLE, Tenn. — Not all pioneers know exactly where they're going, and that was definitely the case for Johnny Cash & the Tennessee Two.

Cash, guitarist Luther Perkins and bassist Marshall Grant — the last surviving member of the group who died Sunday at age 83 in Jonesboro, Ark., after an aneurysm and stroke — changed the future of American music and popular culture with their distinct boom-chicka-boom beat.

Mr. Grant fell ill after rehearsing for a concert to raise funds for the restoration of Cash's boyhood home, said Cash's daughter, Rosanne Cash.

Mr. Grant always freely admitted the soon-to-be historic trio had no special insight as they shaped that …