A Swiss composer and music administrator born in Zurich, and associated with several different musical genres. His output included chansons, classical, and light music. His classical music often combines myriad styles and techniques, including those drawn from baroque, classical, and twelve-tone music. In the 1930's, he studied composition and conducting with Hermann Scherchen in Budapest and Vienna, and later with Wladimir Vogel in Basel.
Liebermann was a friend of the German singer Lale Andersen , a friendship which - since he was Jewish - caused her some trouble with the Nazi authorities during WWII.
Liebermann was the director of the Hamburg Staatsoper from 1959 to 1973, and again from 1985 to 1988. During his tenure in Hamburg, he commissioned 24 new operas, including The Devils by Krzysztof Penderecki, Der Prinz von Homburg by Hans Werner Henze, and Help, Help the Globolinks! by Gian Carlo Menotti. In the intervening years he served as director of the Paris Opera from 1973 to 1980. He died in Paris.