In 1924, Hansen created the tenor role of Baron Kolomán Zsupán in Gräfin Mariza at Hubert Marischka's Theater an der Wien in Vienna.

Hansen was engaged by Max Reinhardt for his revival of Offenbach's La belle Hélène[6] and by Erik Charell for his production of Lehar's The Merry Widow.

Hansen's greatest stage success was in creating the role of Leopold the waiter in Ralph Benatzky's operetta-musical The White Horse Inn, a part he also undertook in Richard Oswald's 1926 silent movie.

Richard Tauber had written an operetta 'Franz im Glück' for him, which was due to be performed at the Theater an der Wien in the 1938/39 season; but the Anschluss in March 1938 put and end to that.

[8] In 1951 he returned to Germany and was successful once again singing the role of Leopold the waiter (The White Horse Inn) in Hamburg and at Berlin's Theater am Nollendorfplatz.