Marx Brothers stage during the middle of a Groucho monologue to see if Groucho would be thrown off. However, to the audience's delight, Groucho merely reacted by commenting, "First time I ever saw a taxi hail a passenger". When Harpo chased the girl back in the other direction, Groucho calmly checked his watch and ad-libbed, "The 9:20's right on time. You can set your watch by the Lehigh Valley." The brothers' vaudeville act had made them stars on Broadway under Chico's management and with Groucho's creative direction—first with the musical revue "I'll Say She Is" (1924–1925) and then with two musical comedies:
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