Otto Klemperer (1885-1973) was director of the Cologne Opera from 1917 till 1924. Between 1954, when he returned permanently to Europe after the war, and 1966 he revisited Cologne on various occasions. This series of live recordings unequivocally demonstrates again how the unique impact he exerted on orchestras and audiences in the concert hall resulted in interpretations that are often more "live" than his famed studio recordings of the same works.