O magnum misterium is Byrd’s SATB setting of this much-loved text. He published it in the 1607 Gradualia, it’s a lovely piece of music in which he conveys his sense of awe and wonder at The Nativity. In the performance below the Cambridge Singers have included Beata Virgo, which although it’s a separate motet, followed O magnum misterium immediately in the liturgy and so was often treated as part of the same piece of music. As with O magnum misterium Byrd wrote very simple and tender music to express the feelings caused by the text amongst the English Catholic community in Elizabethan England. Enjoy :-) .