Beethoven completed his String Quartet op. 135 at Wasserdorf Castle in Gneixenhof, where he sought to recuperate with his nephew Karl after the latter’s failed suicide attempt in summer 1826. It stands out among his late quartets owing to the often cheerful, almost pastoral character of its four movements. Since Beethoven’s death it has often been interpreted as an attempt to take wise and positive stock of the mishaps that had befallen him in the preceding years regarding his life situation, family and health. This interpretation is strongly suggested by the final movement, “Der schwer gefasste Entschluss” (The Difficult Decision), with its motto “Must it be? It must be! It must be!”

The editing of this quartet proved especially complex, for the authentic sources were reworked at various stages by the composer. By judiciously assessing them, editor Jonathan Del Mar has managed to clarify many anomalies found in previous editions.