Here is my translation of the Latin hymn for Apostles, "Exultet vera Ecclesia," an evangelical correction by H. Bonnus of the anonymous "Exultet coelum laudibus," as given in Lossius' Psalmodia (1579). The melody is found in the same source; in transcribing it I have set it in D major and added a ligature between the 6th and 7th note, where one might expect a vocalic elision in the original.
LET THE true Church on earth rejoice,
1. Exultet vera Ecclesia