Became famous along with his sibling Aloys as duo pianists. He premiered many contemporary works for just two pianists because the Klavierduo Kontarsky. He and his sibling performed their initial open public concert in 1949, playing Concerto for just two Pianos by Stravinsky. He and his sibling became teachers in 1962 on the Darmstadt International Summertime Courses for SONGS. His sibling Bernhard would accompany them on shows needing three pianos. He and his sibling performed Debussy’s Petite Collection for 1990’s Henry & June starring Uma Thurman.