Cantor Rabinowitz dreams of his son carrying on the time-honored tradition of serving as a cantor in the revered synagogue located in the Jewish ghetto of Manhattan's Lower East Side. However, life takes an unexpected turn when thirteen-year-old Jakie Rabinowitz chooses to showcase his talent for jazz music at a local beer garden instead. This rebellious act catches the attention of Moisha Yudelson, who promptly informs Jakie's father about his son's performance. In a fit of anger, Jakie's father drags him home, where the boy, terrified, clings to his mother, Sara. The father exclaims vehemently, "I'll teach him better than to debase the voice God gave him!" In a moment of defiance, Jakie threatens, "If you whip me again, I'll run away—and never come back!" After enduring the beating, he shares a tender goodbye kiss with his mother before fleeing, staying true to his word.
During a Yom Kippur service, a somber Rabinowitz confides to a fellow worshipper, "My son was to stand at my side and sing tonight - but now I have no son." As the sacred Kol Nidre resonates through the synagogue, Jakie sneaks home to retrieve a cherished picture of his beloved mother, highlighting the internal conflict between duty and love.
Fast forward approximately a decade, Jakie has adopted the more mainstream name of Jack Robin. In the vibrant atmosphere of a cabaret, Jack is pulled from his table to dazzle the audience with his dynamic stage presence. He captures the attention of the charming Mary Dale, a dancer from the musical theater world. With keen insight, Mary tells Jack, "There are lots of jazz singers, but you have a tear in your voice," and offers her assistance to help propel his burgeoning career. Under her guidance, Jack secures his major breakthrough with a leading role in the much-anticipated musical April Follies.
Back at the family home he once abandoned, a bereaved Cantor Rabinowitz is seen teaching a young student the traditional art of cantorial singing. When Jack returns in hopes of reconciling, he attempts to express his modern musical outlook. However, his father is horrified and casts him out with the scornful command, "I never want to see you again - you jazz singer!" As Jack departs, his heart heavy with love, he prophesizes, "I came home with a heart full of love, but you don't want to understand. Some day you'll understand, the same as Mama does."
Tragedy strikes just two weeks after Jack's expulsion, as his father falls gravely ill just before the open night of April Follies on Broadway. Jack faces the heartbreaking decision of whether to fulfill his duty to his family and perform the Kol Nidre in his father's absence or attend the premiere of his show. On the eve of Yom Kippur, Yudleson informs the Jewish elders, "For the first time, we have no Cantor on the Day of Atonement." From his sickbed, Cantor Rabinowitz confides with a frail voice to Sara, expressing his inability to fulfill the sacred tradition: "My son came to me in my dreams—he sang Kol Nidre so beautifully. If he would only sing like that tonight—surely he would be forgiven."
As Jack preps for a dress rehearsal, slathering on blackface makeup, he and Mary discuss the compelling pressures of career versus family obligations. Just then, Sara and Yudleson arrive at Jack's dressing room, urging him to sing in place of his ailing father. Caught in a whirlwind of emotion, Jack performs his blackface number, "Mother of Mine, I Still Have You," which causes a flood of tears for Sara as she realizes her son has found his rightful place on stage: "Here he belongs. If God wanted him in His house, He would have kept him there. He's not my boy anymore—he belongs to the whole world now."
Shortly thereafter, Jack returns to the Rabinowitz home, kneeling by his father’s bedside for a heartfelt exchange: "My son—I love you." Sara proposes that Jack's performance at the Yom Kippur service may help rejuvenate his father's health. Meanwhile, Mary shows up with the producer, who ominously warns Jack that failure to attend the opening night performance would ruin his career in Broadway. Jack feels trapped. Mary acidly questions, "Were you lying when you said your career came before everything?" Unsure of his ability to replace his father, Jack laments, "I haven't sung Kol Nidre since I was a little boy." Encouraged by his mother, she tells him, "Do what is in your heart, Jakie—if you sing and God is not in your voice—your father will know." The producer reassures him, "You're a jazz singer at heart!"
On opening night, the anxious audience learns the show has been canceled. Stepping into the void, Jack ultimately makes the emotional choice to sing the Kol Nidre in place of his father. From the confines of his deathbed, Cantor Rabinowitz listens to the sacred performance and utters his final words of forgiveness: "Mama, we have our son again." The ethereal spirit of his father appears alongside him in the synagogue, as Mary watches in awe. She recognizes the profound shift within Jack, observing his reconciliation of the jazz singer and his identity as a devout son, "a jazz singer-singing to his God."
As the seasons change and time passes, Jack emerges as The Jazz Singer, headlining the Winter Garden theater, clearly set to be the star of a show entitled Back Room. In a poignant full-circle moment, his mother and Yudleson sit in the front row, witnessing Jack—dressed in blackface—perform "My Mammy," not only for her but for the world, a resounding testament to love, identity, and acceptance.
