Arvo Part's Kanon Pokajanen is a work of starkly radiant beauty, a deeply felt plea for forgiveness so resonant it seems to bear its own expiatory power. The piece is a choral setting of the Russian Orthodox Church's canon of repentance, believed to have been composed by St. Andrew of Crete sometime in the late seventh century. Part had experimented with the canon in earlier works, but when the Cologne Cathedral commissioned him to compose a choral piece for its 750th anniversary, he took the opportunity to immerse himself in it completely. Over two years of intense quality time with the work, Part produced an 80-minute choral setting of the entire canon that mines each word of the original Church Slavonic (a language used exclusively in ecclesiastical texts) for its maximum musicality and meaning.