The hymn text is drawn from the Collection of Masses of the Blessed Virgin Mary, specifically the prayers and scriptural selections for the Advent Time Mass of "The Blessed Virgin Mary and the Annunciation of the Lord." The text is not merely about the Annunciation as a private moment in Nazareth. It repeatedly emphasizes Christ's royal identity:

"wear the regal crown"
"a noble Son"
"The Savior, great Emmanuel"
"the high and Holy One"

The opening paraphrase comes from Rorate caeli ("Drop down, you highest heavens"). 

I have set the text to the tune of ST. THEODULPH (All Glory, Laud, and Honor), I am looking at this tune through the lens of Christ's entry into the world through the virginal womb as a parallel to His triumphal entry into Jerusalem. Both events reveal the coming King, though one in humility and the other in public acclaim. Yet I wonder whether the tune's strong Palm Sunday associations might lead some congregations to think first of Holy Week rather than the mystery of the Incarnation? 

For that reason, I have also considered AURELIA ("The Church's One Foundation"), I like the processional strength of this tune and because it doesn't carry the seasonal associations like ST.THEODULPH does.

As always your thoughts and comments are appreciated. 

The Annunciation of the Lord
Title: Drop Down, You Highest Heavens
Meter: 76.76 D
Tune: ST. THEODULPH (All Glory, Laud, and Honor) or AURELIA (The Church’s One Foundation)

Verse 1
"Drop down, you highest heavens, 
And rain the Just One down; 
Let earth bring forth the Savior 
To wear the regal crown!" 
The Lord has sent His angel
To Galilee's green land, 
To tell how human nature 
Is shaped by God's own hand.

Verse 2
From David's house a Virgin 
Had found the Lord's high grace; 
Though troubled by the greeting, 
She brought relief to race. 
"Behold, you shall conceive Him, 
And bear a noble Son; 
The Savior, great Emmanuel, 
The high and Holy One."

Verse 3
The Virgin heard with pure faith 
The secret Word decreed, 
That Christ among the peoples 
Should come for human need.
The Spirit's power o'ershadowed 
Her pure and spotless shrine, 
Fulfilling Israel's long hope 
In flesh that is divine.

Verse 4 (Doxology)
To God the Father glory, 
To Christ, the Word made flesh, 
To Holy Spirit praise be, 
Who makes our world afresh. 
O source of our salvation, 
Blest Trinity we raise 
With all the ranks of angels 
An endless hymn of praise.

I thought I would try my hand at composing lyrics for a new Advent hymn.  The hymn is called Chosen Daughter of Israel and I set it to the melody WINCHESTER NEW or On Jordan's Bank. 

This hymn draws its inspiration from the Advent liturgies honoring Mary as the Chosen Daughter of Israel. Rooted in Scripture and the Church's prayer, it reflects Advent's promises of salvation, presenting Mary as the faithful daughter of Israel through whom Christ, the long-awaited Savior, comes into the world.

Your thoughts and suggestions are welcomed. Verse 4 (Doxology)
To God the Father, source of might,
To Christ the Lord, our saving Light,
And to the Spirit, Lord of love,
Be praise from earth and heaven above.