As evidenced by the scores to the two movies for which he is most famous "Jean de Florette" and "Manon des Source", Petit's style is very much based on Classical and Romantic traditions. Indeed he adapted a theme from Giuseppe Verdi's "The Force of Destiny" as the main theme linking both movies, and there are some hints of Strauss and opera, overlain with light Impressionist touches and elements of folk music. There seems to be a uniquely French quality to the music, tragic yet whimsical and a touch sardonic, which helps to bring out both the humour and pathos in the story. He uses a harmonica (expertly played as ever by Toots Thielemans) as a kind of substitute for a traditional French accordion, but with that added expressiveness to make the story personal and involving. Strings, woodwind, voice and harp (and the unusual psaltery) get plenty of opportunity to shine in his orchestrations. The main theme has been made famous by its frequent use in television and film adverts for Stella Artois, its mood capturing a stereotypical mix of melancholy and melodrama with a certain "c'est la vie" shrug of the shoulders.
Much of the soundtrack to "Cyrano de Bergerac" seems very classical in its inspiration, though there was a court case claiming a couple of tracks borrowed ideas from Danny Elfman's score to "Batman".
Petit plays an active role in SACEM, the French composer's society.
Petit has also done a lot of work for television including series, TV films and mini series. Most of this has been in his native country, so English speakers may not have much opportunity to experience this work.
It should come as no great surprise that we are going to recommend the two soundtrack albums which make up the complete story of the novel by Marcel Pagnol as made into film by Claude Berri. "Jean de Florette" can be found at these links: Amazon.com in the US or Amazon.co.uk, and "Manon des Sources" can be found at these links: Amazon.com in the US or Amazon.co.uk. In the same way that you must watch both films to learn the full story, you need both albums to appreciate the musical arc of this complete soundtrack.