 Schoenberg substituted the Intermezzo at Zemlinsky's suggestion.A large work consisting of one movement which lasts longer than 45 minutes, Schoenberg's First String Quartet was his first assured masterpiece, and it was the real beginning of his reputation as a composer.Begun in the summer of 1904 and completed in September 1905, this quartet is remarkable for its density and intensity of orchestration with only four instruments.