Bayreuth Festival - Eleanor Steber and Wolfgang Windgassen in Lohengrin with Joseph Keilberth

Unsigned photo postcard showing American soprano Eleanor Steber (1914-1990) and German Tenor Wolfgang Windgassen (1914-1974), shown with German Conductor Joseph Keilberth (1908-1968)  in costume in rehearsal for Wagner's Lohengrin at the Bayreuth Festival. Stamped on verso by photographer Gebauer, Bayreuth. Size is 3.5 x 5.5 inches, in excellent condition.