Matt Lindsay is the owner of a broken-down showboat, perpetually one small step ahead of his creditors and the law. At one point, he disguises himself as Col. Witherspoon, a con artist he'd met earlier, only to find himself in the middle of a blood feud with Col. Beeler, who aims to settle things once and for all—with a pistol.
Riverboat Rhythm was originally conceived in September 1944 as a vehicle for its juvenile musical-comedy team of Glenn Vernon and Marcy McGuire. When RKO suddenly released McGuire, Vernon suggested his erstwhile Broadway co-star Joan Newton to fill McGuire's role. The project was retooled as a Leon Errol comedy along the lines of his Mexican Spitfire features, with Spitfire veterans Charles E. Roberts and Leslie Goodwins writing and directing, respectively. Errol joined the cast in May 1945[4] as "Matt Lindsay," the familiar character he'd played in the Spitfire comedies, and the script gave him opportunities for mistaken-identity masquerades (a Spitfire hallmark).
