Alleluia. Ora pro nobis
From Tallis' early period is the short Alleluia. Ora pro nobis
for four voices. There is clearly a melody in the medius or alto part which means it can be identified as a liturgical text to be sung at Lady Mass (a daily celebration of the Eucharist which used texts relating to the Virgin Mary) on Tuesdays from Pentecost to Advent. The addition of a plainsong opening, or incipit, and the verse ‘Ora pro nobis’ allows a complete performance.
from notes by Andrew Carwood © 2013