Gloria was written in 1974 in response to a commission from The Voices of Mel Olson, a choir based in the USA. The division of the work into three movements â respectively proclamatory, prayerful, and joyfully affirmative â corresponds to the divisions in the text. Most of the melodic material derives from a Gregorian chant associated with this text. An accompaniment for orchestra without organ is also available. The Latin text from the Ordinary of the Mass for mixed voices, brass (4 trumpets, 2 tenor trombones, bass trombone, tuba), percussion, and organ. An accompaniment for symphony orchestra without organ is also available