Schoenberg, Arnold Syllabification: (Schoen·berg, Arnold)Pronunciation: /ˈSHə(r)nˌbərg, ˈSHœnˌberk/Definition of Schoenberg, Arnold (1874–1951), US composer and music theorist, born in Austria. He introduced atonality into his second string quartet (1907–08), while Serenade (1923) is the first example of the technique of serialism. Schoenberg, Arnold in other Oxford dictionaries Definition of Schoenberg, Arnold in the British & World English dictionary