Scelsi is an Italian 20th century composer with an unusual personal story, but the bottom line is that he wrote pieces in the 1960s which were basically all one note. There appears to be something of a 60s psychedelic thing going on here, and perhaps minimalism. Definitely his pieces are more way fun to listen to than something like Revolution No. 9. Listening to a one-note piece like this opens your mind, it’s like staring into a marble and you can see a whole universe in there. Or something.
Anyway, from Alex Ross’ profile:
The music is anything but monotonous; it seethes with change. In the quartets, the players use every trick in the book to transform those long tones, varying the degree of vibrato, bowing over the fingerboard or close to the bridge, adding steel mutes, scraping with maximum pressure. As the tones shift, split apart, and fan out, surprising shapes emerge. In the last part of the Fourth Quartet, a cluster of pitches creeps ever upward, and, in the process, major and minor triads materialize out of nowhere.
Scientific researchers have recently observed a musical event that employs a curiously familiar style: a black hole in the Perseus cluster of galaxies is emitting a B-flat fifty-seven octaves below middle C.
It makes for great temp music, by the way, in a film or video game. It’s worthy of study for composers doing horror cues, there are a lot of techniques at work here with rhythm, dynamics, extended playing techniques. This one-note motif is good for something primordial or ancient.
Here’s Hymnos. Be warned, it’s not elevator music!