So Gloria Swanson picked him, eh? I'm sure she gave him the name of an agent and acting coach and left it at that. Call me if you get movie work, and we'll have lunch!
A fine career was ahead of him:
As soon as Rio Rita was completed, Boles went back to Warner Brothers as the leading man in an even more extravagant musical entitled Song of the West (1930) that was filmed entirely in Technicolor. Shortly after this film, Universal Pictures offered John Boles a contract, which he accepted. He starred in a number of pictures for them, most notably the all-Technicolor musical revue entitled The King of Jazz (1930) and a historical operetta entitled Captain of the Guard (1930). In 1931, he starred in One Heavenly Night (1931), which would prove to be his last major musical.
Boles portrayed Victor Moritz in Frankenstein (1931).
He quit the business in 1952.