In 1937, Heger joined the Nazi Party. Heger conducted one of the final concerts of the Berlin Philharmonic on 12 April 1945 at the Berlin the Philharmonic Hall, 4 days before the Red Army started the Battle of Berlin. The Berliner played Wagner’s Brünnhilde's last aria and the finale from Götterdammerung, Beethoven's Violin Concerto and Bruckner's Romantic Symphony, in attendance of the Albert Speer and Admiral Karl Dönitz. Historical records confirm that members of the Hitler Youth offered cyanide capsules to the audience when leaving the building, to the horror of Albert Speer.
Heger conducted at the Royal Opera House, Covent Garden, from 1925 to 1935, and again with his Munich company in 1953, when he gave the first London performance of Richard Strauss's opera Capriccio. He lived to conduct stereo recordings, notably a fine rendition of Schubert's complete Rosamunde incidental music in the 1960s, before his death at 91 in Munich.
Compositions
Heger composed four operas. His works include:
The Jewess of Worms (melodrama)
Pianoforte trio, op 14
Songs
A Festival at Haverslev (3-act opera, prod. Nuremberg 1919)
Hero and Leander (symphonic drama, full orchestra) op. 12
Violin concerto in D major op. 16
Symphony in D minor
A Song of Peace (choral work for soli, chorus, orchestra and organ)