The core of There Will Be Blood should be readily apparent to anyone who loves metal, especially the epic drone metal of bands like Sun 0)))), Sleep or Om. It is long, concerned primarily with evil, and heavy.
In There Will Be Blood, there is only one character—the rumbling bass note of Daniel Day Lewis's Daniel Plainview, an oil prospector who is more a force than a man. He is not particularly reflective, and the film only gives him two foils to communicate with, and both are removed abruptly.
He is black, oily and essentially simple. For all the praise that Daniel Day-Lewis has received, most of it has been deceiving, given over to the size of the character he portrays (the Onion AV Club note on "Big Acting" is particularly dead on) rather than noticing that he gets some surprisingly subtle moments out of a lumbering beast of a film. While generally, he's just acting the living fuck out of the movie, acting with great effort and attendant bombast and bellow, he's able to draw humor out of his humiliation at the hands of an Evangelical. Conversely, the intensity that he puts into "I DRINK YOUR MILKSHAKE!" makes it as "scary" as Venom's protestations that they are truly evil, in league with Satan.
Add that to Anderson's juggernaut direction, which emphasizes an unresolved and ever mounting tension, spurred on by Plainview's drinking and alienation, and it has the feeling of a particularly turgid metal opera. To strain the metaphor only slightly further for increased accuracy—set that metal opera in Deadwood and you have There Will Be Blood exactly.
Which isn't to say that it's bad, because it's not. It's just unabashedly portentous while being nihilistic about what it portends, and it's interesting to me that this is treated seriously when a lot of metal isn't. It has the same technical virtuosity, the same aesthetic power, the same mythological vocabulary, the same moral fixations (there is arguably nothing more moral than nihilistic art). And this movie is up for the picture of the year, while Pelican's City of Echoes is ignored at the Grammy's?
Where I have to abandon this point is that, like City of Echoes, I didn't enjoy There Will Be Blood all that much. I thought both were interesting, and I'm glad that they exist, and I can put each in its genre context, but they're things that I'd like to think about, rather than experience again. I would urge anyone reading this to see There Will Be Blood on the big screen—I would have abandoned it about ten minutes in on a small screen. But then, metal's better live, innit?