Among others, he wrote new versions for Die Fledermaus by Johann Strauss and Donizeti's Don Pasquale for performances at the house.

[1] Jerger created the role of the Man in Schönberg's Die glückliche Hand at the Theater an der Wien in 1924.

[4] From 1922 to 1959, Jerger often took part in the Salzburg Festival, where he made his debut in the title role of Mozart's Don Giovanni, with Richard Strauss as the conductor.

He also appeared as Sixtus Beckmesser in Wagner's Die Meistersinger von Nürnberg, conducted by Wilhelm Furtwängler in 1938.

[9] Jerger was awarded the title Kammersänger in 1934, and received the Cross (Ritterkreuz I. Klasse) of the Austrian Decoration for Science and Art the same year.

On 8 June 1959 he was awarded the Ehrenmedaille der Bundeshauptstadt Wien [de], and was an honorary member of the Vienna State Opera from 1960.