I am sitting in a room

A man walks into a room, sits in front of a microphone and says the following: "I am sitting in a room different from the one you are in now. I am recording the sound of my speaking voice and I am going to play it back into the room again and again until the resonant frequencies of the room reinforce themselves so that any semblance of my speech, with perhaps the exception of rhythm, is destroyed. What you will hear, then, are the natural resonant frequencies of the room articulated by speech. I regard this activity not so much as a demonstration of a physical fact, but more as a way to smooth out any irregularities my speech might have."
Then he does what he says he would: he plays back the recording of his voice, and records this. Then he plays back that recording, and records it. And so on. Composer and sound experimenter Alvin Lucier's I am Sitting in a Room consists of 32 sequential recordings of the words quoted in the above paragraph, each repetition being less like a human voice and more like a series of ringing tones as "the resonant frequencies of the room reinforce themselves". The version I listened to was recorded by Lucier in his living room in October 1980, and is on Lovely Music. It lasts about three quarters of an hour.
There are some works of experimental art where you just know that simply reading the concept of the experiment will be a vastly more rewarding experience than actually sitting through it. Andy Warhol's 8-hour slow-motion film of the Empire State Building springs to mind. (Perhaps we could establish a big arts prize along the lines of the Turner, but where entrants simply have to submit a 100-word proposal rather than an actual work of art. All the controversy, none of the expense!) But I am Sitting in a Room is definitely one to experience. I was skeptical about whether I'd last the distance, and the first couple of repetitions just seem to have a slightly distorting hum, but the feedback becomes quite strong rather quickly, and it's fascinating listening to the voice disintegrate. After about 15 minutes, the voice is almost unrecognizable, but the rhythm of Lucier's speech remains; the overall effect is rather like an old-style Cylon with its head in a big bell (and who wouldn't pay to see that??). You still can detect a trace of the "irregularities" - a pronounced stutter on a few of the words - though now they're a feature rather than a bug, so to speak. By the end, the overall effect is something like the mysterious throbbing of a giant machine or ghostly noises from the deep ocean. But more significantly, what started out as speech has been transformed into what modern ears are happy to accept as music. In fact you might even start to wonder what would happen if the work went on for another 45 minutes; perhaps some other simple transformation might gradually turn these resonances into something approaching Bach...