A classical art form is bound to have some set expectations that have stayed true through the years, some, all the way from the 18th and 19th centuries - and even earlier! Some may say, "ughh! old, boring.." others appreciate the order, balance and clarity they provide, like the masonry foundation of a house. You know that you can build upward and outward when the groundwork is unshakable. That solid classicism also provides a manual and guide.
It is so with ballet - starting with the most obvious, non-negotiable French terminology for all positions and movements. There are many other traditions that are part of the teaching and learning of classical ballet that have not wavered. For instance, thanking the instructor at the end of class with the reverance, the use of a ballet barre, the use of classical music for class, the use of mirrors to provide instant self-assessment, to name a few.
Some elements have evolved through the years, such as the preferred materials for ballet shoes, the look and style of practice-wear and dance garments, and the way the hair is pulled back from the face. But overall, their purposes are still practical and unquestioned for their utilitarian design.
There are newer traditions that have evolved and actually become re-set in a particular school or studio. For instance, where a dancer stands at the barre during floor-work, who goes first, and protocol for a visiting dancer, among other things. A dancer's spot at the barre is sacrosanct in her home studio. Her place at center is also an unchanging, unspoken mark in space, much like a student's desk in a classroom becomes claimed by a particular student after the first day of class. And a dancer's space in the dressing room is also never to be tampered with - the word 'space' in this case is absolute. There are very firm, unspoken boundaries surrounding where a dancer sets her belongings and follows her preparation routine, such as dressing, mending, medicating, or stretching. For a dancer in the dressing room, her space becomes fixed, solid matter, not to be violated.
Many dancers retain these territorial marks through many years, and feel strongly about them. Visiting dancers do well to stay back until the "home team" takes their spots and choose a place at the barre only after the regulars have done so. It's just common courtesy - and tradition.
There are other unspoken traditions within a ballet class, particularly in the more advanced levels, like seniority, for instance. The most advanced dancers typically take their place in the first row during center work, even if the lines continuously change throughout class, usually the starting point is seniority goes first. Visiting dancers typically take their place at the back, or out of the way, unless invited forward by the instructor.
The show of good sportsmanship is also a strong tradition in ballet class. A dancer always congratulates and cheers on her co-dancers, and does not praise herself or her accomplishments to the others. Humility and quiet pride are paramount in studio protocol, as the opposite - self aggrandizement (or the diva syndrome) spells social suicide. This is particularly true if the dancer is talented. The rule here is that your successes speak for themselves!
In ballet, as in life, it is wonderful to have a history and tradition to buttress your endeavors. Similarly, abiding by some common-sense rules, being aware of others around you and being respectful of their own traditions go a long way toward promoting a healthy and happy environment. Soon, every dancer develops his or her own traditions, and will want others to respect them. Traditions provide stability and boundaries, which add to the sense of trust and belonging dancers feel at their home studio, and owning their art form in general.