Christus resurgens ex morituis

Because we are still in the octave of Easter today, Friday, is not a day of penance marked by abstinence, but a day of rejoicing marked by feasting in celebration of the resurrection of our Lord, Jesus Christ.

Christ Risen, by Peter Paul Rubens, 1616

Accordingly, our traditio for Easter Friday - brought to my attention on the evening of Easter Sunday by a friend of mine who is a priest - is "Christus Resurgens" by the Irish choir Anúna. According to their website, the name Anúna "is derived from the Gaelic term An Uaithne, a collective description for the three ancient forms of Irish music - Goltraí (song of lament), Geantraí (song of joy) and Suantraí (the lullaby)."

Christus resurgens ex morituis (Christ rising from the dead)
Jam non moritur (will never die)
Mors illi ultra (Death no longer)
Non dominabitur (rules, that is, "does not dominate")