What concept did the father of Siegfried Wagner revolutionize?
Siegfried Wagner Siegfried Wagner (6 June 18694 August 1930) was a German composer and conductor, the son of Richard Wagner. He was an opera composer and the artistic director of the Bayreuth Festival from 1908 to 1930.
José Rey de la Torre José Rey de la Torre (December 9, 1917 – July 21, 1994), known by his stage name Rey de la Torre, was one of the most significant classical guitarists of the mid-twentieth century, and considered by many to be the father of "modern classical guitar technique".