An incredible chant with a riveting message.
We begin with the Psalmist urging us to gather to make offerings to the Lord but also make vows and accomplish them. So the entire first line has the sound of urging us to act and sustain that action, with the lingering notes on FA, moving to this tricky liquiscent figure on "circuitu." The first half of the chant ends calmly. And truly it could end there and be very beautiful.
But it doesn't end there. Suddenly, matters become much more serious. We start again on Fa but this time move to La on the text "Terribili" and with no break pass through this firery phrase that is extremely intense with drama, especially once we get to "principum." When you sing that, your voice just feels the intensity and the heat of the moment. Then again we sing the word "terribili" and move through another striking musical phrase the burns with the passion of someone singing about an awesome power. Just to listen to it, you know that the story here has taken on a much greater significance at the end that it began with.
And so what are we singing about? Our vows, we are told, are made to "the awesome God who takes away the life of princes; he is greatly feared by all the kings of the earth." Thus does God stand above all states, no matter how powerful they may appear. God can strike down all earthly power, and so should all earthly rulers live in fear. Who then should receive our vows? The state? Or God?
Is it any wonder that Rousseau considered Christians essentially dangerous to the collectivist-secularist civic order he attempted to create? The chant explains why. At liturgy, we are not singing about the glories of the "general will" but rather about transcendent power that reigns over all. We are loyal citizens, yes, but our first loyalty is to God.
This version will give you a sense of the sound (but probably not the drama).