Gloria tibi Trinitas
is deservedly the best-known of Taverner’s three large-scale festal masses and took pride of place as the first item to be copied into the so-called Forrest-Heyther part-books, thought to have been compiled for use at Cardinal College during Taverner’s tenure of office. Its title is derived from the plainchant cantus firmus ‘Gloria tibi Trinitas’, one of the antiphons for Trinity Sunday and doubly appropriate in view of the College’s dedication to the Trinity. Scored for six-part choir with the high trebles so characteristic of English music of this period, the Mass is a masterpiece of finely balanced construction. Its cantus firmus, assigned to the mean part, is stated three times in each movement, in progressive rhythmic diminution. (The one exception to this pattern occurs in the Agnus Dei, where the expected second statement of the chant is omitted in favour of a freely composed passage of poignant serenity.) As was customary in English festal masses of this period, the Kyrie was not set to polyphony because it would have been sung to troped chant. The four constituent movements, broadly similar in length and outline, are linked by a common head motif. Within each one, variety of texture is brought about through the contrast between sonorous passages for full choir (invariably incorporating cantus firmus) and more delicately scored verses, often more imitative in conception.
The unusual grace that characterizes the section of the Benedictus beginning at ‘In nomine Domini’ was evidently recognized by contemporary musicians, several of whom included it in their anthologies of favourite extracts. Not only was it arranged for a variety of vocal and instrumental ensembles, but it also provided the inspiration for a new genre of major importance. Known as the ‘In nomine’, this instrumental form was distinguished by its cantus firmus, the ‘Gloria tibi Trinitas’ plainchant, and it was widely cultivated by English composers up to the end of the seventeenth century.
from notes by Sally Dunkley © 2000