The Sealed Angel, Shchedrin's monumental choral work - over an hour long - is rooted in the tradition of the large scale liturgical compositions by Tchaikovsky and Rachmaninov, and, like them, is closely related to the ''Znamennyj raspev'', the traditional chant of the Russian Orthodox church. But more than this, Shchedrin's richly varied score unites sacred and secular elements in almost exemplary fashion, the liturgical texts and the flow of the music inspired by Orthodox church music are fused together with interludes played on the flute, which above and beyond its colouristic role, plays the practical part of a pitch pipe for the members of the choir.