This coming Sunday, the Third Sunday of Advent, has traditional been known as Gaudete Sunday, after the introit of the Latin Mass. Rose vestments may be worn and a rose candle is often lit on the Advent Wreath.
Gaudéte in Dómino semper: íterum dico, gaudéte. Modéstia vestra nota sit ómnibus homínibus: Dóminus enim prope est. Nihil solíciti sitis: sed in omni oratióne petitiónes vestræ innotéscant apud Deum. Benedixísti Dómine terram suam: avertísti captivitátem Jacob.
Rejoice in the Lord always. Again I say, rejoice; let your forbearance be known to all, for the Lord is near at hand; have no anxiety about anything, but in all things, by prayer and supplication, with thanksgiving, let your requests be known to God. (Philippians 4:4-6).
Giovanni Vianini, Schola Gregoriana Mediolanensis, Milano, Gaudete in Domino, Tone 1 [YouTube] (preceded by BWV 722)