It's been a little while since I've seen a film by Darren Aronofsky, as I've only really seen Pi (1998) and Requiem for a Dream (2000). Black Swan (2010) certainly follows in their footsteps in its attempt to chronicle a descent into madness, but it does so with more grace, maturity, and artistry. Perhaps I should go back and watch The Wrestler (2008), to which this film is a companion piece, as it will likely show a similar maturation of Aronofsky's style.
Internal rivalry
Synopses of the film often describe a focus on a rivalry between the ballerinas Nina (Natalie Portman) and Lily (Mila Kunis), but I don't think this is really the point of the film at all. It is quite obvious that the film's main focus is Nina herself. This is evident first and foremost by the film's subjective nature. We are always present with Nina, and often the camera literally follows her, peering over her shoulder to see what she sees. I will point out, though, that we do not get actual point-of-view shots. Never do we explicitly enter her head and see exactly what she sees or hear what she is thinking. While we are limited to her, and privy to glimpses of her psyche, we are always removed from her—able to contemplate Nina in ways that she is unable. (This is an important dynamic in the relationship between cinema and its spectators, and one that is excellently handled in Roman Polanski's Chinatown, but I will return to Polanski later.)
At any rate, the "rivalry" seems to exist more in Nina's mind than in reality, and serves more as a part of a greater focus, which is Nina's conflict against herself in her attempt to reach "perfection" as a ballet dancer. This connection occurs time and again as Nina has visions of a doppelgänger, a hallucination which will often incorporate Lily as well. Nina is technically superior but lacks the passion, the ability to "lose herself in the music" like Lily can. As the film unfolds, Lily's role takes on a symbolic position of the darker side of Nina, one that Nina must find and incorporate into herself to reach true perfection.
The Swan Queen as both the White Swan and the Black Swan
You do not have to go into this movie being completely familiar with the ballet Swan Lake, as the film explains the main conceptual elements of the story that are important to the film, but having some understanding certainly wouldn't hurt. In fact, the film could be described as a filmic take on the ballet, as there are numerous parallels. The film is most interesting in how it takes the story to different levels. On one hand, the competition between Nina and Lily for the role of Swan Queen (and thus trying to win the love for the director), could be compared to the original plot, but this reading lacks much added interest. However, if we apply the contest between the White and Black Swan to Nina's own mental struggle for perfection, the original story really does take on new life.
Polanski-esque surrealism
Not surprising for Aronofsky, there is a fair amount of unsettling imagery in this film, and a tendency to play with the boundary between reality and insanity. However, unlike Requiem for a Dream, Black Swan handles this with more subtly and maturity. The dark surrealism has been compared to Roman Polanski's earlier films, and in particular, his "Apartment" triology. It's a comparison I whole-heartedly agree with. Like the trilogy, this film focuses on in the inner psyche of one character and their descent into the darkest depths of their own mind. They all break reality in such a way that, even at the end, we are sometimes unable to sort everything out into neat categories of "reality" and "delusion." Yes, some things are obviously one or the other, but the line that divides them is blurry at best.
As another note, the film is very well shot, and makes excellent use of the handheld camera that has, for better or worse, become a norm (due in part, I'm sure, to reality TV). Often, such jittery camera work feels unnecessary, a mere repetition of a current style without any actual substance, and at first, I feared this might be the case. However, as the film progresses, I saw how the camera seemed to dance with its primary partner, Nina, carrying the ballet theme into the cinematography itself and adding credence to the idea that the film is, in itself, another take on Swan Lake.
Ultimately, the film is well-done. The acting is superb, especially from Portman, who never wanes in quality despite being consistently framed by the camera's lens. The supporting roles are quite good as well, especially Nina's mother (Barbara Hershey) and the director (Vincent Cassel). Mila Kunis did a decent job as well, though perhaps not as well as the other two. Black Swan is certainly a compelling, visceral film. It could also be an excellent change of pace if you want to go to the theatres but don't want the usual Christmas blockbuster fair.