(Credit: holtenau.at) Austrian baritone Rudolf Holtenau has died in Vienna on August 30, at the age of 88. Holtenau, who born in Salzburg, sang a lots of role throughout his career, with an emphasis on Wagner operas. Holtenau began his vocal studies in Linz, and then moved to Vienna where he finished his professional education. He debuted in Klagenfurt, and {…}