Jennifer Holmans of the TNR attempts a difficult contextualization in trying to enunciate the role of tradition and the individual talent within the dance against the backdrop of holding onto a classical dance cannon.
Giselle is not an isolated case. Most ballets have similarly flexible structures and histories that are bound up with the personal biographies of the dancers who performed and staged them. In this regard, classical ballet is a very peculiar art: since it has no written texts, it is not upheld by its own past. Indeed, it has only the most limited access to ages gone by, and cannot claim a body of works that recall its traditions and situate it in the history of Western civilization. Moreover, if a ballet drops out of the repertory for too long, it will disappear: we cannot retrieve it later to reconsider its merits. Fastened to the present, ballet cannot evaluate its own past. A ballet, even a "classic" ballet, is now, or it is forgotten. For this reason, ballet cannot have a canon in the way that drama and music do.
This does not mean that ballet does not have its own tradition of sacred texts. Indeed, it might be said that as a tradition ballet exists somewhere between showbiz and the priesthood. Showbiz, because ballet is constantly subject to the exigencies of getting a show up on stage and pleasing an audience. As such, it is perennially in the grip of contemporary fashion and taste: sylphides and Wilis on wires were sensational effects in the early nineteenth century, but they would look hopelessly dated today.
Even if one is not an aficionado of the dance, it is not too hard to gain sufficient understanding of how the modern dance evolved as a need to break out of the bounds of the classical forms. (My own epiphany on the matter came during a production of Don Quixiote some years back).
Nevertheless, I wonder if Holman's thesis on the role of the cannon is not more backlash against the licentiousness that encompasses a lot of modern offerings rather than a wholesale re-affirmation of the classical cannon or even a purpose of pointing out the need to re-interpret the classics.
In any case, here is Sylvie Guillem and Manuel Legris : Grand pas classique, with choreography by Maruis Peptia's, who is mentioned in the article. It gives, I hope, both a sense of the triumph of the "classique" and its truncations.
sullylink