This is only one example of the disconnect due to the current way the Mass is popularly practiced, with choirs using popular “Entrance Songs” instead of what the Church has primarily prescribed. The Introit should have provided a lot of this information. It’s not the fault of the Novus Ordo itself, but is rather due to a lack of appreciation of the value of the texts themselves, such that planners have tried to make the Mass more “popular.” But if only the Introits were chanted again, even after the “Entrance Song”:
Gaudete Sunday of Advent:
Rejoice in the Lord always; again I say, rejoice. Let your forbearance be known to all, for the Lord is near at hand; have no anxiety about anything, but in all things, by prayer and supplication, with thanksgiving, let your requests be known to God. Lord, you have blessed your land; you have turned away the captivity of Jacob.
Laetare Sunday of Lent:
Rejoice, O Jerusalem: and come together all you that love her: rejoice with joy, you that have been in sorrow: that you may exult and be filled from the breasts of your consolation. Psalm: I rejoiced when they said to me: 'we shall go into God’s House.
Just reading the Introits would tell you the themes of the Masses, and why there is a “break” in the middle of Advent and Lent.