This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Arvo Part worked within Soviet Estonia's musical avant-garde through the 1960s, composing in the twelve tone and collage techniques current among his contemporaries. His 1968 choral and orchestral work Credo, built on an overtly religious text, was banned by Soviet authorities, a direct collision between the explicitly religious content of one composition and the officially atheist state under which Part was working.
After the ban, Part stopped composing publicly for several years, a documented silence he spent studying medieval and Renaissance polyphony rather than continuing to write new work for performance. During that same period he converted from a nominal Lutheran upbringing to Orthodox Christianity in 1972, a religious change that coincided with his years of study rather than following some separate, later course.
Part re-emerged in 1976 with tintinnabuli, a self invented minimalist technique built from simple triads, ending a silence that had run from the Credo ban through his conversion and his study of early polyphony. The sequence, an overtly religious composition banned, years of study and religious conversion, and then a new technique built from the material he had spent that silence studying, is documented as one continuous episode in his own career rather than as separate, unrelated developments.