I know everybody appreciates different kinds of music, but I'm afraid I find this kind of music hard to appreciate. Maybe it's just me.
Anyway, Arnold Schoenberg (1874-1951) was considered the leader of a new group of composers at the beginning of the 20th century that wanted to change music forever. He began his musical career writing pieces that sounded somewhat melodic, similar to those of Wagner, Mahler, and Strauss before him. You know, like where you can almost tell what key they're in? But after years of stretching tonality almost to the breaking point, Schoenberg finally decided to break it once and for all---he started writing a new kind of music that wasn't in any key whatsoever. This kind of music was atonal. Atonal music is dissonant, meaning it sounds like the "wrong" notes are being played. And Schoenberg went even further than that after awhile. He started using rules of math to write his music. Today, this kind of music is referred to as 12-tone music, or serialism.
A while ago, I came across a very funny article by David Pogue, New York Times Columnist and former Broadway music director, and Scott Speck, award-winning music director and conductor, that explained Schoenberg's musical method. It's so good, here it is word for word:
If you find middle C on a piano and play all the white notes in order up to the next C, you've just played the seven notes in the key of C. About 99 percent of the world's music has been written in the key of something. That's why so many pieces of classical music are called such things as Symphony in D major or Sonata in F.
But notice something about the key of C: In traveling up the piano from C to shining C, you skip all the black keys. Arnold Schoenberg's big concept was that these keys shouldn't be second-class citizens just because they're a different color. His new kind of music, 12-tone music, used all 12 of the notes between C and C, white and black---equally. Sure, some of the old-fashioned concepts such as 'harmony', 'melody', and 'pretty' went out the window, but that's progress.
Not only did Schoenberg decide that all those previously ignored in-between notes deserved more importance, but he actually instituted the world's first affirmative-action quota system for those notes. He decided that if he wrote the note C on his music paper, he wasn't allowed to use a C again until he'd used all 11 of the other notes first!
After he saw how intellectually satisfying such self-imposed rules were, he went even further. He'd make up a specific order of those 12 notes---for example, C, E-flat, G, A-flat, B, C-sharp, B-flat, D, F-sharp, F, A, E---and force himself to use these notes in that order, over and over again, for an entire piece. He'd permit himself to use whatever rhythms he wanted, and he was allowed to combine the notes into "chords"---but he always went in order.
When things were getting really dull, he made up a couple more rules: Playing the series of 12 notes backward was okay, too. He even permitted himself the luxury of flipping a 12-note series upside-down on the music paper. And for years and years, he had all kinds of fun mixing up these rules to make music (such as playing those 12 notes backward and upside-down).
This new kind of music was dubbed 'serialism', which has almost nothing to do with Schoenberg's passion for whole-grain breakfast flakes.