Listen to O Mary of Graces online. O Mary of Graces is an English language song and is sung by The Cistercian Nuns of St. Mary's Abbey Glencairn. O Mary of Graces, from the album In Praise of Mary - Marian Hymns and Chant, was released in the year 2007. The duration of the song is 2:52. Download English songs online from JioSaavn.