Michael Haneke, the art house-beloved German director probably best-known for Funny Games and Caché, has something of a reputation as a provocateur (probably because of... Funny Games and Caché) that he doesn't quite deserve. Not because his films aren't sometimes provocations; but that is, I think, incidental. Better to say that his is a filmmaker of extremes, not in the high-gore, high-shock sense used of Asian exploitation film, but rather that he tends to focus on extreme situations, as the basis for character study and social commentary.

Viz: The Piano Teacher (a rather flimsy translation from the French La pianiste), Haneke's 2001 consideration of the corrosive effects of sexual repression, embodied here by Erika Kohut (Isabelle Huppert). Erika teaches piano at a conservatory, having never quite managed to make a career for herself as concert pianist, for reasons that are not spelled right out in the film: possibly it's just that she's not quite good enough, but it seems equally likely that a successful career in the arts would have run afoul, like presumably a great many other things in her life, of her mother (Annie Girardot), an ill-tempered woman who lives with Erika in a small one-bedroom apartment. The teacher's general impatience for her life, and her unstated anger at never having made it big as a soloist herself, can be easily guessed at by quick observation of her treatment of her students: though we certainly would never expect a good conservatory professor to freely hand out soppy praise when good sense and constructive criticism are of greater value, Erika's words to her students verge more on abuse and scorn.

The film eases us in slowly: first a scene that merely introduces Erika and her mother, then a montage, of sorts, intercut with the opening credits, that demonstrates her pedagogical style, then a sequence in which she gives a chamber performance at a party, suggesting that this is the closest she can ever come to fulfilling her actual goals. This sequence also introduces us to Walter Klemmer (Benoît Magimel), an enthusiastic engineering student with a love of classical music that Erika politely describes as "precocious", although "snobbish" comes closer to the mark. So far, Haneke is keeping the heat on low, letting us get a feel for Erika's life without really giving us a sense of where things are going: the opening of the film is as wandering and plotless as any art film you would like to name.

Then, quite without fanfare, about one-fifth of the way into the movie, Erika enters a video store, waits in line patiently next to a stand of tapes with half-dressed (or less) women on the covers, and then walks into a private booth. She briefly considers the selection of movies and then selects a video showing a woman in nothing but a halter top lying on her back, fellating a standing man. Erika watches the porno with absolutely no expression - she has the same tight-lipped look on her face that she wears when berating a student - and then reaches into a wastebasket, pulling out a cum-drenched tissue and sniffing it.

So: provocative? Of course it is - even in Europe, you can't just drop a literal pornographic movie right into the middle of your art film without it being a provocation. But this isn't just Haneke twitting or titillating the audience, and if it is shocking, it's because we are suddenly and without warning shown a side of this stern, unhappy woman that comes from absolutely nowhere. That is, for the audience it comes out of nowhere: the rest of the movie, when not detailing further the extent of Erika's warped relationship to sex (which includes spying on couples at drive in movies, and in the film's most notorious scene, taking a razor blade to her genitalia, with the same rough amount of passionate intensity that she brings to everything else: that is to say, absolutely none at all), explains by implication how a middle-aged woman has ended up so utterly incapable of pursuing her sexual urges in a healthy, straightforward manner. The easy answer is: her harridan of a mother, but nothing about The Piano Teacher is easy. Erika herself is no gem of a human being, and her curdled view of humanity is revealed slowly, never through explicit statement, and relying in no small degree on the immense skill of Huppert's performance.

Ah, Isabelle Huppert! If you are unfamiliar with this treasure of international cinema, then you truly do owe it to yourself to seek out her work as quickly as possible; if you know her already, then you do not need me to explain that she is one of the greatest living actors. And while I have not seen many of her films, I do not speak lightly in saying that her work as Erika is the single finest performance I have ever seen her give, and therefore almost by default one of the best of the decade. With Haneke refusing (correctly) to give us too much in his screenplay, it falls upon Huppert to really make Erika come to life in all of her terrifying subterranean urges, and the actress does not let the movie down for a split-second. Everything about her curt line delivery, her refusal to ever smile or let any other trace of happy emotion flicker across her face or her body, and the very certain way that she stands, rigid and uncomfortable, explains all that we need to know about Erika: she is sad and alone, but full of lusts and desires; she cannot think of any way to deal with people other than to dominate them with her implacable severity. She is as sympathetic and pitiable as she is terrifying, and without this incredibly well-judged performance, there would be no movie: without this performance, there would be no Erika, and Erika is the movie.

As the plot progresses, and Erika rather expectedly falls into a sexual affair with Walter, we see the full flower of her crippling inability to express herself, and the awful ramifications of this fact, which becomes more or less the "message" of The Piano Teacher: repression will out, and it cannot help but do so violently. But I will not say more of this, in favor of letting the viewer find out for themselves. It is a troubling, unpleasant film, but completely engaging nonetheless, and entirely free of the stillness and sterility that sometimes unjustly make "French-language art film" such a damn hard sell in the anglophonic world.

Considering that Haneke's bread and butter is the conspicuous, mechanical and deliberately alienating subversion of traditional film grammar, The Piano Teacher is unexpectedly straightforward: other than some curious audio bridges, the most obvious of which occurs during the first porn-watching scene, there's really nothing in this films that violates the aesthetic norms of sound cinema in the 1930s, to say nothing of the 2000s. It's as if, just this once, the director concluded that his subject matter was enough to put the audience through a violent emotional wringer that he didn't need to add any upsetting, unlikely violations of cinema in order to give the film that extra kick of meanness. He's right: it doesn't take anything other than Huppert's immaculately tight performance to give the film its woozy effect, and all that the director needs to add is a refusal to come close enough to the blood that the audience can have a restful moment of comfortable disgust, as well as a repeated motif of shots that stress the angular, graphic, cage-like feeling of Erika's world. It is a movie whose sickening impact is achieved through the simplest means, a controlled and impressively disciplined character study that needs nothing more than that character to crawl under our skin.