1557

Gabrieli's O magnum mysterium consistently and classically counterpoises two contrasting vocal choirs while maintaining its elegant proportions. Gabrieli divides his text, which celebrates the lowliness of Christ's birth on Christmas, into three unequal parts; each receives a musical section of roughly equal length. The opening phrase, "O great mystery," is sung three times: once by the first choir, once by the slightly lower second choir, and a third time in climactic full polyphony. The second phrase of text, which explains that the great mystery and "wondrous sacrament" allowed mere animals to see the birth of the Saviour, takes the same tripartite structure, with a temporal broadening into triple rhythmic groups. The composer packs the most text into the third section, which extols the manger and the blessed Virgin; twice Gabrieli cycles the contrasted vocal choirs, once aspirantly starting with the lower ensemble and rising to the heights. The choral antiphony becomes thus not only a vehicle for grand effect, but also serves to articulate the very structure of the text and to embody its sense. The radiant conclusion of his motet comes in a fourth section, an extended jubilant "alleluia." A series of syncopated, triple-meter antiphonal statements gradually gives way to a broad, eight-voiced tutti. Whether the two choirs braved the logistical challenges of physical separation or merely sang in proximate alternation, the effect added great luster to the Venetian liturgy.