Final answer:
Arnold Schoenberg was a late-century critic who often advocated for absolute music.
Step-by-step explanation:
One of the late-century critics who often advocated for absolute music was Arnold Schoenberg. He was an Austrian composer known for his innovations in atonality and the twelve-tone scale. Schoenberg's experiments with dissonance and unexpected notes challenged traditional musical expectations and had a significant influence on avant-garde musicians and composers.