The Latin Second Typical Edition (1991) of the Order of Celebrating Marriage contains the following rubric at the very end of the Order of Blessing an Engaged Couple found in Appendix II:

271. Celebratio laudabiliter cantu apto perficitur.
or
271. It is a praiseworthy practice to end the celebration with a suitable chant.

If someone were celebrating this Order of Blessing according to the Latin Second Typical Edition, what might be a suitable chant if the Order of Blessing is to take place during the penitential season of Lent on a Friday due to the limited availability of out-of-town family members who will be present? Because of the lack of an accompanist and the small number of people in attendance, the chant needs to be sung a cappella. It needs to be easy enough for all to sing it comfortably even if they are not quite familiar with it (a score will be provided). Although the rubric doesn't specify that the chant must be Gregorian chant or the word "chant" could be taken to mean songs in other styles, the preference is that a chant that is Gregorian or informed by Gregorian chant must be chosen. The chant should be a simple chant of thanksgiving or praise offered to God. Initially, the simple English Te Deum seemed to fit the bill, but it doesn't seem appropriate to sing the Te Deum on a Friday during Lent. Does anyone have any suggestions for an another appropriate chant to be sung following the Order of Blessing an Engaged Couple celebrated on a Friday during Lent?