Marx Brothers and the Marx Brothers. Most of the comedians provided their own voices for their animated counterparts, except for Fields and Chico Marx (both had died), and Zeppo Marx (who had left show business in 1933). Voice actor Paul Frees filled in for all three (no voice was needed for Harpo). The Marx Brothers' segment was a reworking of a scene from their Broadway play "I'll Say She Is", a parody of Napoleon that Groucho considered among the brothers' funniest routines. The sketch featured animated representations, if not the voices, of all four brothers. Romeo Muller is credited as having written
Marx Brothers Cream" sketch. In a 1969 interview with Dick Cavett, Groucho said that the two movies made with Thalberg were the best that they ever produced. Despite the Thalberg films' success, the brothers left MGM in 1937; Thalberg had died suddenly on September 14, 1936, two weeks after filming began on "A Day at the Races", leaving the Marxes without an advocate at the studio. After a short experience at RKO ("Room Service", 1938), the Marx Brothers returned to MGM and made three more films: "At the Circus" (1939), "Go West" (1940) and "The Big Store" (1941). Prior to the release