A mesmerising a cappella choral composition by Sergei Rachmaninoff. It's in Old Church Slavonic and literally means "Virgin Mary, Mother of God, rejoice" or "Hail Mary, Hail". You can consider it as a Slavonic version of Ave Maria or Hail Mary Prayer.
I did the Tenor 2 part for this piece with my Rhythmos choir during second semester last year. It was absolutely beautiful to hear all the different voices come together in this piece. The biggest challenge for me when recording this is obviously to learn how to properly pronounce the words. There are two things that I'm not too happy about in this recording, 1) еси is supposed to be yesí, not esí, 2) My tuning kept dropping and towards the end, it's almost a semitone lower than the original F major key.