Waltzes from Vienna opens with the sound of a fire brigade horn and the clip-clop of horses’ hooves as the firemen race toward Ebezeder's Café. Upstairs from the cafe, Resi [Jessie Matthews] and Schani [Esmond Knight] are immersed in a tender love duet that ends with Schani telling Resi he has dedicated his newest song to her. At the same time, Countess Helga von Stahl [Fay Compton] is shopping nearby, drawn to the music from the corner shop. The moment of private romance is interrupted when Leopold [Hindle Edgar], a baker in Resi’s father’s café, climbs a ladder in a clumsy bid to rescue Resi, driven by his own feelings for her. The two men quarrel over who should save her, and Leopold ultimately wins the dramatic save, hoisting Resi over his shoulder as her skirt slips along the climb. Resi bolts toward the dressmaker’s, while Schani retrieves her skirt and stumbles into the shop in search of Resi, where he crosses paths with the Countess. When the Countess learns Schani is an aspiring musician, she quietly offers to have him set her verses to music, planting the seed of a dangerous artistic opportunity.
With romance sparking and ambition rising, the drama shifts to the orchestra where Schani serves as second violin under his father, the elder Strauss [Edmund Gwenn]. The elder’s baton is a symbol of decades of tradition, and tensions flare when Schani insults his father’s music to his stand partner. The elder Strauss overhears and commands that Schani perform one of his own pieces for the orchestra. Rather than offer a respectful display, Schani is ridiculed, prompting the elder to declare that his son could never have a legitimate career as a composer. The confrontation pushes Schani to quit the orchestra, severing the safe path laid out by his family.
Buoyed by a newfound independence and the Countess’s commission, Schani visits Resi at her father’s bakery to share the big news. Resi, initially brisk and practical, warns that if he wants to marry her he must give up music and take over the bakery. Yet when she glimpses the Countess’s verses, she is swept up in the musical potential and even sings the opening of The Blue Danube waltz, drawing Schani deeper into the idea of composition. The moment becomes a living, collaborative act: a basement kitchen becomes a studio, and the rhythm of the dough, croissants, and a spinning dough mixer inspires the waltz’s themes. As Schani surveys the bakery’s chaotic energy, the melodies begin to emerge—two main themes taking shape in the cadence of bread being tossed, each loaf shaping a beat, each machine providing a heartbeat. He rushes upstairs to tell Resi that he has completed the piece, a triumph tempered by the cost of leaving music behind.
The couple’s triumph is tempered when the Countess arrives to hear the new waltz, and Schani performs for her first, quickly followed by a performance for a publisher, Anton Drexler [Marcus Barron]. The Countess’s seductive praise becomes a glittering trap, and a duplicitous dedication erupts: Schani’s page, initially dedicated to Resi, is replaced by a second page dedicated to the Countess. This betrayal is heard by Resi, who feels the sting of Schani’s divided loyalties even as the two lovers reconcile—Schani vows to give up his music to work in the bakery. Yet the taste of success lingers, and the lure of the Countess’s world pulls at him, even as Resi’s devotion remains a counterpoint to his ambition.
As the romance and music unfold, Schani finds himself drawn back to the stage at the Countess’s invitation to St. Stephen’s Festival. Resi warns that attending the festival could spell the end of their relationship, but the Countess schemes to keep the elder Strauss late so Schani can step in to conduct his new waltz in his father’s place. The moment of truth arrives as Schani leads the festival performance of The Blue Danube Waltz. The elder Strauss is late, the crowd roars, and Schani takes the conductor’s stand, delivering a performance that captivates the audience but provokes a tempest behind the scenes.
After the concert, the elder Strauss confronts Schani about the unauthorized performance, and the couple’s fragile balance collapses into confusion. Schani exits in a swirl of doubt, while the Countess pursues him, intent on maintaining her control over his career. Resi arrives in time to intervene, slipping in through the back to expose the Countess’s ruse. The Countess returns to the front stairs, only to find Resi stepping into the spotlight as the crowd outside hums The Blue Danube Waltz. In the end, the music and the lovers’ resolve align: Resi’s steadfast love remains, and the waltz—born in a bakery’s chaos and shaped by a family’s doubt—finds its home in the heart of Vienna’s enduring melody.
