One of contemporary classical's bestsellers, this Estonian composer's body of work is both heartbreakingly fragile and deeply contemplative. He began his career as a staunch serialist, using the style's dissonance as protest against his Soviet government. However, by the end of the '60s, Part's style shifted to what he calls "tintinnabulation," or the sound of bells. Marked by a minimalist focus on subtle, exact tone, his musical language harkens back to the simple, deep harmonies of early music while remaining absolutely modern. The music does not change key throughout the course of a given composition, giving the work its characteristic timeless, meditative quality. Themes of repentance and rebirth surround much of his work, which, choral work in particular, is unabashedly spiritual and absolutely sublime.