This internationally renowned French pianist specialized in contemporary music, but he also excelled in the performance of traditional repertoire by Mozart, Beethoven, and Schumann. Helffer began his piano studies at the tender age of five. The famous Robert Casadesus was impressed by his playing and took him on as a student. During WWII, he pursued advanced studies at l'École Polytechnique. Helffer participated in the Resistance in the underground fighting at Vercors, for which he was awarded the Croix de guerre in 1944. (His other decorations include Chevalier de la Légion d'honneur, Officier de l'ordre du Mérite, and Officier des Arts et Lettres). After the hostilities, Helffer was finally able to graduate from l'École and made a final decision to make music his career. He then studied harmony and counterpoint with René Leibowitz and gave his debut recital in Paris. In 1954, he became associated with the Domain Musical Orchestra and championed contemporary music by playing the works of Barraqué, Serocki, Evangelisti, Luciano Bério, Pierre Boulez, Philippot, and Karlheinz Stockhausen. Compositions such as Epigrammes (1965) by Amy, a concerto by André Boucourechliev (1975), Stances (1978) by Betsy Jolas, Manoury's Chryptophonos (1974), Erikhton by Iannis Xenakis (1974), Luis de Pablo's Concerto No. 1 (1980), Envoi (1982) by G. Tremblay, and the Modifications (1983) by Jarrell (1983) bear dedications to Helffer. In 1962, he played for the first time in Latin America and made his American debut in 1966 with the Chicago Symphony. He debuted in Russia in 1968. In 1978, he was engaged as a professeur d'interprétation at the Music School of Vienna. Helffer made his debut in Australia in 1980 and in Japan in 1984. He has continued to perform throughout the world with many well-known conductors, including Barshai, Boulez, Bour, Gielen, Iwaki, Maderna, Marriner, Martinon, van Otterloo, Prêtre, Scherchen, Sebastian, and Tabachnik. Helffer also held master classes in piano music interpretation in Europe, North and South America, Australia, and Japan. He was a member of the editing committee on a critical edition of the works of Debussy for the Durand-Costallat publishing house, he presided over a revision of the composer's two books of preludes and the etudes, and published several volumes of pedagogical studies.