For all the Swan Lake music featured in the film—set as it is during rehearsals for an upcoming new production of Tchaikovsky's famous ballet—I would suggest that the real musical/spiritual precursor of Darren Aronofsky's new film is Maurice Ravel's La valse. Just as Black Swan begins as a fairly realistic backstage drama with occasional surface disturbances and eventually transforms into a full-on surreal nightmare, so does the great French composer's brilliant 1920 "poème chorégraphique" build in moments of tension to break up its initial aura of Johann Strauss-like gracefulness, gradually build to a pitch of crazed intensity and finally explode in a hallucinatory swirl by its concluding moments.
I have more to say about the film—which is a total blast, by the way—but for now, if you haven't seen it and want an idea of what the experience of watching it is like...well, look—or rather, listen—no further.
Oh, and then, you can turn to another Black work—the 1947 Michael Powell/Emeric Pressburger masterpiece Black Narcissus—for a cinematic equivalent. Because, to my mind, that's, in many ways, a more relevant point of comparison than the oft-cited The Red Shoes. The former may not have ballet in it...but it has built-up repression, and lots of it, as does the lead character of Black Swan.