1946: Graduated as a philosopher at the Haverford College. Had also studied English literature. Then went to Paris, represented his country at the first UNESCO festival where he performed the 5th piano concerto by Beethoven. A tour followed (Rome, Vienna, Naples, Paris, London, Salzburg). After that he settled in Paris.
1956: Married Arlette Patoux
Katchen's popularity increased in the period 1949-1969 and had a varied repertoire for Decca with piano music of Brahms.
In December 1968 he was part of a project by the Rolling Stones Rock and Roll Circus.
He died less than six months later as a consequence of cancer at only 42 years old.