Many ordinary-use parishes are pleased to introduce the first set of sung ordinary chants, usually from what the Liber Usualis labels the "Mass for the Dead," or Mass XVIII, or what is included in the Jubilate Deo as the only Mass setting in the first edition (and don't you find it interesting that that is what modern missalettes call their "chant Mass"? the Mass for the Dead? get the hint?) but don't know where to go after that. Many settings seem too daunting in parishes where people are socialized to believe that they must always sing the Ordinary and it must be simple and easy to pick up right away.
So I thought I would share with readers the success we've had with the following Agnus Dei from the "additional chants" section of the Kyriale (page 162 of the Gregorian Missal). It is in the 6th mode, and is easy enough to sing after hearing one time but interesting enough to entice the ears and hold up over time. The melodic line repeats three times with no variation. Watch the half step between Fa and Mi after the incipit. It is a very beautiful and singable Agnus that would work in most parishes environments. It requires no accompaniment: