Hymn of Kassianí (medieval version), sung during the Orthodox Holy Week
From the album Hymns of Kassianí (Capella Romana)

Old Roman chant - Terra Tremuit
Ensemble Organum, directed by Marcel Peres
Album: ‘Chants De L'Eglise De Rome Des VIIe Et VIIIe Siècles. Période Byzantine’ 

‘Of Bodies and Spirits: Soundscapes of Byzantine Thessaloniki’
Produced by Olya Dubatova and Chris Kyriakakis