Q: Is it mandatory to chant the Sanctus and Agnus Dei during Lent or Advent? Our music director does this even though almost no one in the congregation does; I don’t think many of us know Latin well enough.
A: No, it’s not mandatory. Many places do it, but no Latin is ever required. GIRM 41 recommends that people learn how to sing the Creed and the Lord’s Prayer in Latin, but many churches sing the Sanctus and Agnus Dei instead.