A few months ago the musical world observed the centennial of the first complete performance of Richard Wagner's Der Ring des Nibelungen, which took place in the then barely completed Bayreuth Festspielhaus, August 13–17, 1876. Few works of art have had so long a gestation period; more than a quarter century separates Wagner's original sketches, which date from the fall of 1848, and the realization of the tetrology on the stage. The dramatic structure of the enormous music-drama became definitive by February 1853, when Wagner allowed to be printed privately the texts of the four operas. The music for Das Rheingold, Die Walküre, and the first two acts of Siegfried was complete by the end of July 1857. There followed, however, an interval of almost twelve years before Wagner again took up work on the Ring in March 1869. He composed the music for the final act of Siegfried and for all of Gütterdämmerung between then and November 1874.