[5] She studied at the Royal Academy of Liège, and in 1914, at the age of 13, entered the Conservatoire de Paris, which was then headed by Gabriel Fauré.
By now she had begun to establish herself as a piano soloist, appearing with leading chamber musicians and with the Concerts Colonne, but she gave up her musical career completely to raise her family of five children.
[7] After 25 years away from professional music, Thyssens-Valentin resumed her career in 1951, with a performance of the Mozart concerto in which she had made her debut as an eight-year-old.
The conductor for her return concert was Albert Wolff, through whom she was introduced to the director of the Salzburg Festival, where she made her first appearance the following year.
[10] She continued to promote the works of Fauré in later years, including by teaching masterclasses and creating a fingered edition[11] of the first eight Nocturnes.
"[13] Thyssens-Valentin retired in 1983; her last concert, in November of that year comprised music by Bach, Mozart, Beethoven, Fauré and Debussy.
[10] Though Thyssens-Valentin was little known outside France during her lifetime, the reissue on compact discs of her Ducretet-Thomson recordings, particularly those of Fauré's music, brought her to a wider international audience.