Blessed are those that be undefiled

THIS PIECE. Somehow I've never shared this as part of my Early Music Monday series, and it's time. This is the piece that started my love of polyphony. Eighteen-year-old me nearly drove off the road when the "Gloria" began and I had to pull over and finish listening.

Blessed are those that be undefiled in the way and walk with the Lord. Blessed are they that keep his testimonies and seek him with their whole heart, for they that do no wickedness walk in his ways. Thou has charged us, O Lord, that we should diligently keep thy commandments. O that our ways were made so direct that we might keep thy statutes. So shall we not be confounded while we have respect unto all thy commandments. - Psalm 119:1-6