Cadenza is one of the four tritagonists of Beauty and the Beast (the others being Lumière, Cogsworth and Mrs. Potts).
Beauty and the Beast (2017)
In the opening of the film, Cadenza is seen playing the harpsichord at the Prince's ball while his wife, Madam de Garderobe, sings. Then when the Prince refuses to give shelter to an old beggar, she reveals herself to be an Enchantress. She curses the Prince to take the form of a beast, and she also curses the castle staff, with Cadenza turned into a harpsichord and his wife turned into a wardrobe.
Years later, Maurice, just fresh from a wolf chase, stumbles upon the castle. He hears a harpsichord playing and follows the sound to the ballroom. When Cadenza notices Maurice is looking at him, he immediately douses his candles and falls silent. Maurice is still unnerved, eventually trying to escape from the castle grounds. But he is intercepted and imprisoned by the Beast.
Later, after Belle takes Maurice's place as a prisoner, Lumière decides to arrange a dinner spectacle for her despite the Beast's orders. He recruits Cadenza to make music, but Cadenza is at first unsure of his playing ability. When he tests it out, he is stopped by "another cavity". Lumière reminds him that if he is ever to see his wife again, he must help Belle feel welcome. He is convinced and promises to play despite the "dental pain", but Cogsworth requests that he play quietly so as not to alert the Beast. The harpsichord sarcastically agrees and asks if there are any other "tasteless demands" that Cogsworth has in mind.
After a successful dinner, Belle wanders into the the West Wing and is frightened away by the temperamental Beast. Later, when Belle is rescued from wolves by the Beast, she takes him back to the castle to nurse him back to health. When Belle inquires the staff as to why the Beast is as selfish as he is, they tell her that when his loving mother died of the plague, he was taken under the wing of his cruel father, who shaped him to exact version of himself.
Later, Cadenza laments and wonders if he will ever be with his love again. His hopes are renewed when Belle and the Beast start to grow closer to each other. When they share a dance, Cadenza plays a romantic song for the two. But when the Beast lets Belle go to help her father, Cadenza and the rest of the staff begin to lose hope and begin to accept their fate of forever being antiques.
That all changes when Gaston and an angry mob invade the castle, looking to kill the Beast. During the ensuing battle, Madam de Garderobe joins the fight. Cadenza is overjoyed to see his wife again. The staff wins the battle against the mob. But when the last petal falls from the Beast's rose, they all begin to lose their human essence. Cadenza watches in sadness as his wife becomes an ordinary wardrobe shortly before turning into an ordinary harpsichord.
Miraculously, when Belle confesses her love for the Beast, a villager named Agathe, who is revealed to be the Enchantress, lifts the curse from the castle, restoring the Beast and the staff to their human forms and the castle to its former glory. Cadenza is happily reunited with his wife and they play together at Belle and the Prince's ball.