O rex gloriae is a motet for Ascension and was published initially in the now lost 1563 book
Motecta festorum totius anni … but subsequently reprinted elsewhere. The joyful element of the Ascension is what gives this motet its character: the phrase ‘qui triumphator hodie super omnes caelos’, for example, is given pointed emphasis by being resonantly set in homophony after the consistently contrapuntal texture of the music up to that point. The phrase is nevertheless then developed contrapuntally and dominates the central part of the motet. This is dramatically followed by the other face of the Ascension—Christ’s parting from mankind—in the semitonally inflected phrase at ‘ne derelinquas nos orphanos’ which is subsequently echoed then varied, inverted, and expanded before a return to the triumphant mood at the final ‘Alleluia’.
from notes by Ivan Moody © 1989