it's musical evolution... according to Schönberg and the 2nd Wiennese School (where the 1st being Mozart, Beethoven)...
after the outbrake of the 1st world war in 1914 the world to many europeans wasn't the same... the concepts of happyness, sadness and the whole tragic war wasn't encompassed in the expressions available to artist in the world of music... - and on that background Schönberg developed this new method of composition, which was in fact meant to be the direct evolution of the previous compositional styles "available" at that time... - the tonal world of the neoclassisists wasn't able to express the emotions of that time... a break was needed... and this new method opened up a whole new world - starting with the dodecaphony and continuing over pure serialism - where also such things as note-lenghts and volume (forte, piano markings etc.) was included in "rows" - "rows" also being used in connection with the 12-tone/dodecaphony system - where the additional "rows" in total gives us this "serialism"...
the pioneer in applying this thinking to a computer-environment where the whole "universe" in a sence, is open to interpretation, is Stockhausen - try to listen to some of his "Studio"s for instance - just have in mind that it's the infancy of computermusic