The plot summary was based on a screen continuity in the UCS Cinema--Television Library. Many of the reviews of this film noted similarities to well-publicized events of the previous year involving John Barrymore and Elaine Barrie. According to modern sources, as the alcoholic Barrymore was recuperating in a New York hospital in Feb 1935, he received a note from nineteen-year-old Hunter College student Elaine Jacobs, who requested an interview with him. After he invited her to visit, she returned daily, and soon Barrymore, who was separated from his wife, Dolores Costello, moved in with Jacobs and her mother. Jacobs dropped out of college and, changing her name to Barrie, became Barrymore's protégée. As their romance grew, they also experienced periods of difficulty, culminating in Barrymore's escape by train for California in Sep 1935. After a reporter alerted Barrie to Barrymore's flight, she boarded a plane to Chicago and, when she missed him there, continued to Kansas City, all along the way making headlines, as did the pet names they called each other, "Caliban" and "Ariel." In Sing, Baby, Sing, the pet names become "Romeo" and "Juliet." While Barrie did not catch up to Barrymore on that trip, they married in Nov 1936, and they were subsequently divorced in 1940.
       This film, unlike others made by Twentieth Century-Fox at the time, begins with the statement, "The events and characters depicted in this photoplay are entirely fictional and any similarity with actual persons, either living or dead, is not intentional but purely co-incidental." Despite this, Barrymore threatened to sue the studio, according to MM. Frank S. Nugent of NYT remarked in his review, "Twentieth Century-Fox, with delightful impudence and its tongue in its cheek, solemnly disclaims any factual basis for its new musical comedy, Sing, Baby, Sing, one of the most amusing pictures shown at the Roxy this year." Var commented that Menjou, in this film, "is obviously doing a caricature of John Barrymore, but it's all in such good fun no one could mind that." No information has been located concerning the results of Barrymore's threat to sue.
       This was the Ritz Brothers' first feature. According to Los Angeles Boulevard Record, studio head Darryl Zanuck signed them after viewing their act in a Hollywood nightclub. Reviewers noted that the film contains bits from their nightclub act, including a Dr. Jekyll and Mr. Hyde parody, with the Frankenstein monster thrown in, an acrobatic-operatic aria, and, according to Var, a "satire on Ted Lewis and the half-wit Harry Richman."
       This was to be the first Twentieth Century-Fox film of Tyrone Power, who was signed to a long-term contract by the studio in May 1936 and cast for the role of "Ted Black." He was replaced after production began, however, by Michael Whalen. While a news item in May 1937 reported that he asked to be taken out of the film, modern sources state either that director Sidney Lanfield fired Power, whom he considered too weak for the role, or that Zanuck, after viewing rushes, felt that the film needed a "name" actor in the role. Modern sources also state that star Alice Faye originally urged Zanuck to cast Power in the role.
       According to HR news items, Fred Allen was originally cast for role of "Nicky Alexander." When he became ill in Apr 1936, the studio at first considered Adolph Menjou, who at that time had not yet been cast as "Bruce Farraday," and Ted Healy. After the studio settled on Healy, whom they borrowed from M-G-M, they closed a deal with Gregory Ratoff, who was in Paris at the time, for the role. The studio then tried to get Fred Allen or Jack Oakie for the role of "Al Craven," but because neither were available, Healy got the role. This was the first role of note for singer Tony Martin, who in 1937, married Alice Faye. According to a HR news item, Patsy Kelly was borrowed from Hal Roach's company. Helen Wood is listed in HR production charts as a cast member, but her participation in the final film is doubtful.