 He began studying music at the Franz Liszt Academy of Music before leaving Hungary in order to study in Rome.When he left Rome in 1959, he established himself in Germany, first in Augsburg and later in Cologne.In the late 1960s and early 1970s, Kelemen was a favorite singer of Herbert von Karajan, with whom he recorded "Fidelio" in the role of Don Pizarro, "Der Ring des Nibelungen" as Alberich, "Boris Godunov" as Rangoni, "Die Meistersinger von Nürnberg" as Fritz Kothner, "The Merry Widow" as Mirko Zeta, and others.