O Magnum Mysterium (223.01) (The music of Giovanni Gabrieli (ca. 1557-1612) has become a staple in the repertoire for modern brass musicians/ensembles. Most are familiar with his popular collections: Sacrae Symphoniae I, published in 1597, and Sacrae Symphoniae II, published posthumously in 1615. Both of these collections include works for different sized vocal and instrumental forces. Gabriels setting of "O Magnum Mysterium" comes from an earlier collection of masses and motets, including compositions by Giovanni and his uncle Andrea Gabrieli titled, "Concerti di Andrea, et di Gio: Gabrieli Organisti della Serenissima Sig. di Venetia 1587." The choral works in this collection call for 6, 7, 8, 10 and 12 voices. "O Magnum Mysterium" is the final piece for eight voices (No. 32) appearing in the collection. The editor suggests an antiphonal set-up of the two brass choirs for performance whenever possible, as was the custom for services at San Marco Basilica in Venice.)