East Slavic Church Music

East Slavic church music is the sacred choral tradition of the Russian, Ukrainian and Belarusian Orthodox churches: chant of Byzantine descent, sung unaccompanied, and its composed polyphonic repertoire. From the znamenny chant of medieval Rus it developed through the partesny concerto of *Nikolai Diletsky* and *Maxim Berezovsky* to the sacred concertos of *Dmitry Bortniansky* and the Romantic liturgical cycles of *Pavel Chesnokov*, *Alexander Gretchaninov* and *Sergei Rachmaninoff*, whose "All-Night Vigil" of 1915 is its most recorded work. Deep oktavist basses and a cappella sonority define its sound.