There were very many art disciplines presented in this movie, mainly because the story itself focuses around a large group of artistic people who work together. Some of the art forms that are shown are 1) singing 2) ballet 3) music (instrumental) and 4) art (back-drops etc).
Many things would be particular about the life of a dancer at the Paris Opera Ballet in the 19th century. The students would start dancing with that program at a very young age (as young as three.) They would be taken from their parents, and live in the school itself. During the day, they would attend a variety of classes from different instructors. Their schedules would be strictly adhered to, as to when they attend what class, when they are allowed to eat, and when they are allowed to spend time outside the classroom. The original building where the school was located burned down in the 1700s, and they relocated to a different building.
When I was studying with the Royal Academy of Dance (based in England) my instructor showed us a DVD of the Paris Opera Ballet School to inspire us as a class. This particular school was very well known (as well as the Kirov Academy in Russia) as one of the top schools that turned out the best dancers. The discipline that these children were expected to have at such a young age astounded the world. They were the best.