The polyphonic settings of the Ordinary of the Mass we have chosen are not specific to any occasion, nor were such settings organized into unified cycles until the late Middle Ages. The Kyrie is based on the popular "Kyrie orbis factor" tune still used today ... The bold, ebullient Gloria succeeds despite carefree violation of proper word accentuation. From a somewhat later time (the early 14th century), the Sanctus and Agnus dei are both based on plainchant and stress ensemble irtuosity. The Ite missa est is a gem of brevity.
With the exception of the virtuoso three-voice setting of the Alleluia: Virgus ferax aaron, the rest of the Mass Propers ... are set in plainchant of the highest art. In the Middle Ages, sequences (settings of double-versicle poetry with a rhyme scheme aa bb cc, etc.) were written in great numbers for local usage, the most beloved of them becoming popular throughout Europe. Among the finest and most expressive of these are two found in the 13-century Dublin Troper: O maria stella maris, attributed to the French poet/musician Adam of St. Victor (d. 1192), and Pangat melos grex devotus[/i, which closes this recording. The Offertory Recordare virgo mater (for the Ladymass on the actual feast day of the Assumption) has been troped, or enlarged, with a 12-line rhymed poetic setting after the normal Offertory text. Even the closing word "Alleluia" is troped.
The medieval motet presents an approach to text setting that is the antithesis of plainchant's unity, with two or three different poems sung at the same time over an untexted tenor that is derived from plainchant. Four-voice texture was relatively rare at that time, and, to our ears, had a somewhat higher rate than polyphony in two and three parts .....
(Susan Hellauer, liner notes)