Johannes Brahms was until now widely regarded as the archetype of the «absolute musician». Based on new research, the study shows how close autobiographic and poetic elements are in fact linked to his oeuvre. Like Robert Schumann, Brahms subscribed to an aesthetic of «poetic» music. In many of his compositions he got his inspiration from personal experiences, poems or images, as is shown by hitherto unpublished documents, letters, and diary entries, as well as from close analyses of individual works. Brahms's personality, too, is seen in a new way. He adopted Joseph Joachim's motto «Frei, aber einsam», «Free but Alone». The tonal code F - A - E, the musical symbol of this, recurs frequently in his works.