The previous post lightly touched upon 2 aspects in Babbitt's composition: electronic music and the total serialism, or integral serialism. Babbitt, more than anyone else, represents a pinnacle, an apex and a maximum of the total serialism. For him, the music's "atomic" event is located in a five-dimensional musical space determined by pitch-class, register, dynamic, duration, and timbre.(*1) All five dimensions can (and must?) be serialized. -- After all, if one can/has to serialize the pitch classes, why not other elements of music?
But -- can you hear it? In my own (admittedly limited) experience I have yet to meet a musician who claims to be able to hear totally-serial music and analyze it in her/his head without studying the scores.(*2) If this is universal truth, totally-serial music has stopped being an auditory experience. Like literature, it has "progressed" from the oral to the literacy tradition. In other words, a book requires no "reading out loud". So why should music be "performed"? Can music survive or even prosper in the form of Augenmusik (eye music)?
(I do not claim to have an answer for these questions. Time will tell. One thing I am sure, though, is that the mathematical naivety in some (many(?), most(??)) of the serialists' papers is indeed alarming....)
One short comment about Milton Babbitt's contribution to the postwar serialism movement: I felt that he was unjustly slighted by his European counterparts in the Darmstadt School. After having established the theoretical foundations in his 1946 "dissertation" The Function of the Set Structure in the Twelve-Tone System, Babbitt composed Three Compositions for Piano in 1947. There the duration was already "serially" controlled. In 1948 he turned his attention to other elements of music in Composition for Four Instruments. In Darmstadt, the first totally-serial work, Olivier Messiaen's Mode de valeurs et d'intensités was composed in the summer of 1949, while Boulez's Structures for two pianos and Karlheinz Stockhausen's Kreuzspiel did not appear until 1951 or after. Of course, their techniques are very different. Nonetheless....
(*1) Quote from Milton Babbitt: Who Cares if You Listen?
(*2) If you are one, let me know please! :)