Jacques Viret (born 19 October 1943) is a contemporary French musicologist of Swiss origin. Life Born in Lausanne, Viret is a pianist and organist, graduated in classic literature from the University of Lausanne, habilitated for the teaching of music theory (Société suisse de pédagogie musicale), Jacques Viret perfected his studies in musicology at the Paris-Sorbonne University, with Jacques Chailley who conducted his Ph.D. thesis on gregorian chant (1981). Since 1972, Jacques Viret has been teaching musicology at the university of Strasbourg, as an assistant and then lecturer and professor, emeritus since 2009. Gregorian chant and medieval music The research and reflection of Jacques Viret refer essentially to the notion of tradition as defined by René Guénon in the line of the perennialism (or Gnosis): Not as the preservation of a fixed legacy, more or less ancient, but as the manifestation, diversified according to cultures, epochs and disciplines, of a "sacred, universal and timeless truth", a fruitful source of inspiration and creativity, in perpetual becoming and renewal. For music, Pythagoras remains, in this respect, a permanent reference. The series of harmonics thus appears, as an audible expression of numbers and proportions, as an image of the cosmic order. The universal creative principle is symbolized by the fundamental frequency in the har:monic order, by the tonic of the modes in the melodic order (all traditional music is of modal essence). In particular, the tonic sol, "sun" in Latin, the central element of the theological and esoteric cryptogram that Jacques Viret discovered in 1978 in the notes of the range (ut, ré, mi, taken from the hymn to Saint John the Baptist Ut queant laxis) and of which Jacques Chailley completed the explanation. The official liturgical chant of the Roman Catholic Church, the Gregorian chant is especially the expression par excellence of tradition for the music of the West. Jacques Viret studies it in this light. He highlights, upstream, the rooting of this corpus in the other musical traditions of the world, especially oriental (and, probably, the ancient celtic music; Downstream, its importance as a breeding ground for European music, both scholarly and - in part - folkloric. This truly traditional approach illuminates Latin liturgical chant in its true light and allows the rediscovering, as far as possible, of its authentic interpretation (cf rhythm) before the year 1000, which is very different from the style instituted in the Nineteenth by the Benedictines of