American burlesque performer Steve Martin (William Demarest) offers to play a song for his audience, if they agree to sing along. Only one person does sing, a young boy named Asa Yoelson (Scotty Beckett). Steve is bowled over by the boy's voice, but Asa realizes he should be singing at the synagogue with his father, Cantor Yoelson (Ludwig Donath). Asa arrives late, and is later reprimanded by his strict father. Asa is reluctant to explain where he was, but Steve Martin visits the Yoelsons' home. He explains that he heard Asa sing at the burlesque house, and that he wants Asa to be part of his act. Papa Yoelson refuses to consider it.