1973 THE UNANSWERED QUESTION Lecture 5 "The Twentieth Century Crisis"

Lecture 5 picks up at the early twentieth century with an oncoming crisis in Western Music. As these lectures have traced the gradual increase and oversaturation of ambiguity, Bernstein now designates a point in history that took ambiguity too far. Twelve-tone music emerges as one potential solution to the crisis, but Bernstein considers this idiom so ambiguous that it destroys the all-important balance between clarity and ambiguity.

He takes issue with the increasing preference among composers for twelve-tone music, because even though at its core it rejects tonality, twelve-tone is nonetheless unquestionably tied to the tonal system. This unintended connection to tonality can be explained by the harmonic series and musical phonology.

First of all, tonality is innate, and twelve-tone music systematically fights with this innate process. Overtones are present whether the music is tonal or twelve-tone, so the importance of a perfect fifth within the overtone series, and by extension, the circle of fifths, is contrary to twelve-tone writing. Also, because of the natural hierarchy of musical pitches, truly equalizing all notes is impossible. As long as the composer is working within the Western Music tradition of twelve notes per octave, tonal relationships still exist. Despite the attempt at establishing a new organization of pitches, composers will inevitably write with tonal implications.

https://en.wikipedia.org/wiki/The_Unanswered_Question_(lecture_series)