[citation needed] He studied ethnomusicology with Jaap Kunst between 1950 and 1954[2] and the encounter with the Dagar brothers and Drupad on his first visit to India in 1961 deepened a lifelong interest in "transculturation".
Since then he has travelled throughout the world: Japan, Indonesia, Australia, the Philippines, Persia, the Sovjet Union, Hungary, Bulgaria and Finland, where he hold workshops and lectures on the East-West relationship in music.
In the seventies De Leeuw and André Jurres initiated the renowned Music-Cultural gatherings Musicultura at Queeckhoven House in Breukelen, the Netherlands.
Plainsong is introduced in his “Psaumes pour la Messe des Morts” [Psalms for the Requiem Mass], as well as dramatic effects where the beating of the tam-tam comes up against the ostinatos of the marimba, against the calls of the female voice.
Ton de Leeuw wrote about 160 compositions, spanning the whole range from solo pieces to complete operas, but it is the vocal and, more specifically, the choral works which reveal most clearly what he was striving to obtain: a conjunction of the essence of past and present, a link between Eastern and Western thought, and the result was a unique purity of expression.