Agathe and Regis have a little boy, Benoît, who is very capricious and sometimes aggressive. The couple, on the verge of divorce, is planning to go on vacation in order to better reflect on their decision. To do this, Agathe and Regis publish an ad in a newspaper: "Young couple seeks au pair grandmother to take care of little boy, 10 years old...". An old lady, Rose, shows up. She arrives with a fish and a bird she can't part with. The first contacts with Benoît are very unpleasant. Not discouraged, she realizes that he is unhappy and that he suffers a lot from feeling unloved in his family.

The film follows four families, with different nationalities (French, German, Russian and American) but with the same passion for music, from the 1930s to the 1960s. The various story lines cross each other time and again in different places and times, with their own theme scores that evolve as time passes. The main event in the film is the Second World War, which throws the stories of the four musical families together and mixes their fates. Although all characters are fictional, many of them are loosely based on historical musical icons (Édith Piaf, Josephine Baker, Herbert von Karajan, Glenn Miller, Rudolf Nureyev, etc.) The Boléro dance sequence at the end brings all the threads together.

A businessman leaves his country home, and wife and young son for a business trip to Paris. While there he develops a sexual and spiritual bond with a call girl.

For 25 years now, under the Provence sun, Antonin, a farmhand, has shared his work and everyday life with a horse named Ulysse. What a shock when Pascal, the farmer, tells him he has decided to sell Ulysse to a picador for being too old. Not only will he be separated from his faithful companion, but he is well aware too that the arenas of Arles mean death for Ulysse. Being unable to stand such injustice, Antonin runs away from the farm in the company of Ulysse. Together, they go through the Lubéron, the Baux de Provence, the Alpilles, the Crau and the Vaccarès. Yet, their journey is no pleasure cruise, specially when it comes to crossing National Road 7. After a visit to Marcellin, an old friend of his, Antonin sets off again with Ulysse, this time towards the Rhône River.

On the day Jean Gabin dies, a kidnaper who also takes a fortune in jewels heisted from Cartiers murders Simon Verini's wife. (Simon was fencing the jewels for a youthful gang who robbed Cartiers; he suspects them of the murder.) He's framed for the theft and spends ten years in prison, writing to his daughter, Marie-Sophie, who's 11 when he's sent away. Released, he reconnects to Marie-Sophie and to the young thieves, seeks revenge, and is quickly arrested again. She doesn't know what to make of her father, retreats to her Swiss fiancé, and is flummoxed when one of the young thieves falls for her. Is resolution possible when crime cuts across families and romance?

Yan is a successful artist. One day he is waiting for his date Florence to turn up at his apartment. As the doorbell rings, he finds another young woman in underwear on his doorstep: his neighbor Eva! She tells him she locked herself out of her apartment and insists that he helps her. Whilst Yan is trying to enter Eva's apartment via their adjoining balcony, his phone rings. It is Florence, and she is not impressed when a female voice answers the phone. At this point, Eva's rabidly jealous boyfriend Boris returns home. Seeing Yan in his apartment, he deduces that Eva has been having an affair behind his back. Florence then turns up and Yan tries in vain to explain the situation. By chance, Florence's husband suddenly puts in an appearance. After that, it all starts to get a bit complicated.

After serving as an embassy secretary in London at the end of 1787, a position he didn't exactly enjoy, the poet André Chénier returns to Paris. When the Revolution breaks out, he becomes enthusiastic about it, and never ceases to express his love of liberty and high principles. But he also speaks out against excesses and troublemakers. For her part, the beautiful Aimée de Coigny, who has just divorced the Duc de Fleury, leads a dissolute life. In 1793, the Convention decides to put "the Terror on the agenda". Aimée de Coigny and her new lover, Casimir de Montrond, are arrested. At the Saint-Lazare prison, their life together is preserved. Six months later, Chénier is arrested and imprisoned. Dazzled by the young woman's beauty, the poet dedicates his most beautiful verses to her. But Aimée remains unmoved by his love.