Not necessarily French. For example, Tchaikovsky's Russian string quartet II in D major is the most beautiful classical music known in the world. Mendelssohn's Violin Concerto in E minor is slightly sad but more romantic. When we mention this song, we have to mention bruch's violin concerto No.1 in G minor. The Dance of Polonaise by Tchaikovsky yevgeny onegin is the noblest dance music I have ever seen. Finally, it is recommended that Han Deer's Water Music is cheerful and romantic music. I think these songs are ok. I continue to recommend them.

French composers are as follows

Debussy's girl with flaxen hair in the moonlight (Debussy's works and her appreciation are the best)

Fantasy caprices in the first and second movements of Berlioz symphony fantasia.

Ravel's peacock dance for the Dead Princess (Sharon's famous song is slightly sad)

Song of Bicai Flower

Introduction of Saint-Sang Swan and Rondo Capriccio and Tarantella

All the above works are more or less sad. If you want simple and cheerful advice, Mozart is better, or a simple Strauss waltz.