Orchestra
While all this is taking place another whole group of people have been busy. These are the musicians who produce the music. It is true that some ballets exist without music, but generally speaking music is one of the most important elements of a ballet.
Sometimes the work on the music starts with a composer being commissioned to write the music for the ballet, but if the ballet has been done before or is being done to an already existing piece of music, which is much more common, the work on the music will start with the orchestra rehearsing. The orchestra will learn and rehearse the music before they ever play it for the dancers so that they always get it right. Playing music for dance is very demanding because not only must the musicians know the music so that it is beautiful and moving, but they must also play at the speed that the ballet masters and choreographers want the dancers to dance at. This speed changes during the course of a ballet, and must be the same each performance for the dancers to be able to do and look their best.
Once the orchestra is all rehearsed, knows the music, and the conductor has found what speed the music is to be played at, it is time for the ballet to move into the theatre.
