 Complete the following phrase:  Widor probably composed the Symphonie VI between his return from a visit to Bayreuth in 1876, where he attended the first Bayreuth Festival, presenting the first performance of Wagners Der Ring des Nibelungen, and the summer of 1878. He premiered it for the inauguration of a Cavaillé-Coll organ at the Palais du Trocadéro in Paris on 24 August 1878 as part of the 