Yesterday, our schola sang the Introit for the Feast of Christ the King (yes, it's October, we use an older calendar): "Dignus est agnus...". You might know the English text from the Handel setting: "Worthy is the Lamb that was slain...". Here is a source text for the Introit: Revelations 5:12:
...dignus est agnus qui occisus est accipere virtutem et divinitatem et sapientiam et fortitudinem et honorem et gloriam et benedictionem...("Worthy is the lamb who was slain to accept power and divinity and wisdom and strength and honor and glory and blessing..."). I was daydreaming during the long sermon and noticed a bit of word-painting in the Gregorian melody. Words referring to earthly power, such as "virtutem," tend to be lower in pitch (and with a Fa tonal center), whereas words referring to spiritual characteristics such as divinity or wisdom have a higher tonal center (either So with the hard hexachord, or La).
At that time, the priest then started addressing the Gospel reading in his sermon, which was from Pilate's interrogation of Jesus in John 18. It's worth repeating part of the interrogation here (John 18:33-38 NAB):
So Pilate went back into the praetorium and summoned Jesus and said to him, "Are you the King of the Jews?" Jesus answered, "Do you say this on your own or have others told you about me?" Pilate answered, "I am not a Jew, am I? Your own nation and the chief priests handed you over to me. What have you done?" Jesus answered, "My kingdom does not belong to this world. If my kingdom did belong to this world, my attendants (would) be fighting to keep me from being handed over to the Jews. But as it is, my kingdom is not here." So Pilate said to him, "Then you are a king?" Jesus answered, "You say I am a king. For this I was born and for this I came into the world, to testify to the truth. Everyone who belongs to the truth listens to my voice." Pilate said to him, "What is truth?" When he had said this, he again went out to the Jews and said to them, "I find no guilt in him.Jesus never gives a straight answer to Pilate's question, "Are you a king?" The most interesting response to me is, "You say I am a king." To me, this suggests that Pilate didn't understand what Jesus meant by "My kingdom does not belong to this world..." Pilate understands "king" in particular as the potential leader of a revolt against Roman rule in Palestine, but more generally as a secular ruler: someone who deals in worldly power. Jesus understands "king" entirely differently: "You say I am a king. For this I was born and for this I came into the world, to testify to the truth." His dominion is voluntarily accepted by his subjects: "Everyone who belongs to the truth listens to my voice."
The word painting in the Gregorian introit melody hints at the story of Revelations, which is the Son of God assuming his authority over the world. He accepts both power over the "lower" earth, and the divinity which is rightfully his from the beginning. I've suggested to Gregorian scholae that they keep in mind the Throne Room March in Star Wars while singing this introit. Both pieces have a heroic minor mode, and both tell the story of victory and authority over evil obtained through suffering and sacrifice. The hero comes before the throne to receive the power and grace that was his by birth, which he relinquished for a greater cause and now receives once again with even greater honor. In that sense, one can read Jesus' saying, "You say I am a king," as a willing relinquishment of his rightful title. He could have claimed it and the honor and power that were his due, but he chose to lay it down instead.