How old would Klaus Tennstedt be today?

Klaus Hermann Wilhelm Tennstedt was a German conductor from Merseburg. Known for his interpretation of the Austro-German repertoire, especially his sympathetic approaches towards Gustav Mahler, Tennstedt is widely considered one of the greatest and most influential conductors of the late 20th century. He worked with the Swedish Radio Symphony Orchestra, the NDR Symphony Orchestra, and other highly regarded ensembles such as the Berlin Philharmonic Orchestra, and most notably the London Philharmonic Orchestra (LPO), which he was the principal conductor of from 1983 to 1987. With the LPO, he recorded extensively, including a complete cycle of Mahler's 10 symphonies for EMI.