Early music vocal ensemble EUOUAE makes their debut at Old First Concerts under the direction of Steven Sven Olbash, who has prepared new performing editions for many of the pieces on this innovative program. The Messe de Tournai is the oldest polyphonic setting of the Mass to have been collected under one cover, predating even Machaut’s monumental Messe de Nostre Dame, and ranges in style from chant-like simplicity to virtuosic vocal pyrotechnics. This performance of the rarely heard Mass will include Gregorian chant for the Feast of the Assumption of Mary sung according to the early staffless notation found in various 10th century manuscripts from the Monastic Library of St. Gall (Switzerland), as well as organum from the 12th century Magnus Liber of Léonin.