With charisma, outsized singing and a fast horse, Al Jolson rides home a winner in this opened-up screen version of one of his biggest stage hits. The dynamic entertainer puts on blackface makeup to portray likable Gus, a stableman-turned-jockey who overcomes adversity and wins the Kentucky Derby after gamblers conspire to have him fired from his mount Big Boy. The role gave Jolson a chance to immerse himself in two of his great passions: the racetrack and singing, with audience-pleasers including Tomorrow Is Another Day and Liza Lee. The ebullient Jolson didn't like one of the songs in the original stage score, so he gave If You Knew Susie to Eddie Cantor. It became wide-eyed Cantor's biggest hit!