A young man walks into a café and hears the Merry Widow Waltz being played for the first time. He immediately buys a copy. Music in hand, he forgets everything and hums along the way. Soon, he's amused to see two policemen start waltzing! He passes a house and hears a young girl playing the fashionable waltz on the piano. Irresistibly, he starts dancing, taking a lamppost as his partner. Then, in front of an organist, a horse tied to a cart also begins to waltz in a wild, unpredictable style. Finally, our young man returns to his room and sits down at his piano to play the tune. But he's barely begun when everything in the room starts waltzing wildly. Then, to his great surprise, the piano itself joins in, and as the boy continues to play the instrument, he finds himself lifted into the air!