The title and lyrics are drawn from the Introito (Entrance Antiphon) for Laetare Sunday: "Laetare, Ierusalem: et conventum facite omnes qui diligitis eam" (Rejoice, Jerusalem, and gather together, all you who love her).
Before diving into the technicalities of the , it is essential to understand the "why" behind the notes. Rallegrati Gerusalemme Frisina Spartito