In 1949 Rieger was announced as the chief conductor of the Munich Philharmonic Orchestra by the city government, replacing the modernist Hans Rosbaud who had been appointed by U.S. occupation authorities. According to author David Monod, the decision to release Rosbaud and replace him with the "young and relatively unknown but suitably conservative" Rieger was caused by a desire to attract larger audiences with more traditional programs, a necessity in the wake of currency reform in the western part of Germany. In 1952, Rieger announced that the orchestra would eliminate almost all modern music from its concerts. Rieger continued to lead the Munich orchestra until 1966.
Monod, David (2006). "Americanizing the Patron State? Government and Music under American Occupation, 1945-1953". In Riethmüller, Albrecht. Deutsche Leitkultur Musik?: Zur Musikgeschichte nach dem Holocaust. Stuttgart: Franz Steiner. pp. 47–60. ISBN3-515-08974-8.