Precisely those qualities, and the integrity which engendered them, won Brahms the esteem of one of the most famous 20th-century progressives, Arnold Schoenberg, the originator of serialism.
That was in 1963, at a time when the classical-music establishment was still in thrall to the postwar professoriate of Austro-German composers and their foreign epigones who believed that the future of music lay not with traditional harmony but with Schoenberg-style serialism.