Johannes Brahms' piano sonatas were among the 20-year-old composer's first publications. They were written in 1852-53, with the slow movement of this C major Sonata, which used the song “Verstohlen geht der Mond auf,” bearing the earliest date, April 1852. With this passionate and highly virtuosic Sonata, Brahms introduced himself to the great of the musical world of his day, including the Schumanns in Düsseldorf. Clara Schumann wrote afterwards that “... the whole is full of exuberant fantasy, intimacy of expression and mastery of form.” Brahms' op. 1 now appears in a separate Henle Urtext edition, revised using the musical text of the Brahms Complete Edition. The sonatas op. 2 and op. 5 will follow.