Renaissance. Victoria's rich, mysterious and serene 4-part Christmas motet O Magnum Mysterium was written in 1572. The composer intended it to be sung at another service later in the year. It has become a Christmas tradition for many choirs. Andrew Converse has arranged this beautiful 4-minute work of moderate difficulty for 202.00 brass quartet (2 trumpets & 2 trombones). An additional horn substitute for the trombone 1 part has been included as well. -the publisher