At the Paris Conservatoire he attended Jean Rivier and André Jolivet classes for composition. He was at first drawn to the serial technique but from 1966 on he turned to another mode of inspiration. Of André Jolivet he said: "As a professor, he has never tried to influence me, nor push me toward any special kind of style. Our professor-student relationship was of a spiritual order. Yet through his suggestion and what Rivier had said, I came to realize that it was in the oriental way of thinking that I would find my style in music. I owe to Rivier the language and the shaping of my music which, as Jolivet has said, should be "a mean to express ideas and not an aim in itself.".
Tôn-Thất Tiết's music has a special language in which both oriental and occidental trends are fused, although the inspiration and thoughts are drawn basically from oriental sources. This is obvious in many of his works such as Kiem Ai (Universal Love, 1978) for choir and orchestra, The Game of the Five Elements, (1982–1990), or Prajna paramita - the basic sutra of Buddhism - for 6 voices and instrumental ensemble, (1988) and Chu Ky, a series of seven instrumental pieces.
Tôn-Thất Tiết composed the scores for Trần Anh Hùng's three feature films: The Scent of Green Papaya, Cyclo, and The Vertical Ray of the Sun, and has also collaborated with French choreographer Régine Chopinot on two of her dance pieces: Parole de feu (1995) and Danse du temps (1999).
In 1993, he founded the France-Vietnam Music Association to promote the development of traditional music in Vietnam.
- (Vietnam), Trung tâm nghiên cứu quó̂c học (2005). Tié̂ng Hué̂, người Hué̂ & văn hóa Hué̂. Nhà xuá̂t bản Văn học. p. 194. Retrieved 22 March 2011.
- [tranquanghai.multiply.com/journal/item/221 TRẦN QUANG HẢI - TÔN THẤT TIẾT, Compositeur vietnamien, France] "29 avr. 2008 – TÔN THẤT TIẾT (1933 - ) Né à Huê au Vietnam en 1933, Tôn Thât Tiêt se rend en France en 1958 pour approfondir les domaines de l'écriture ..."
- Tiết Tôn-Thất - Bibliothèque nationale de France "Compositeur français d'origine vietnamienne. Adopte la nationalité française en 1977. Directeur de l'Association France-Vietnam pour la musique"
- Southwest Chamber Music [PDF "12 Oct 2010 – composer Tôn-Thất Tiết. The piece reflects on the soundscape of life in Vietnam with the rolling and sometimes pulsatory flow of the river and ..."
- ensemble intercontemporain "... musicologue et éditeur, parle du Silence dans la musqiue de Tôn Thất Tiết ..."