His birth is still rendered in words by Isaiah, followed by the annunciation to the shepherds as the only scene from a Gospel in the oratorio, and reflections on the Messiah's deeds.

For Messiah, Handel used the same musical technique as for those works, namely a structure based on chorus and solo singing.

Two trumpets and timpani highlight selected movements, for example in Part I the song of the angels Glory to God in the highest.

Handel often stresses a word by extended coloraturas, especially in several movements which are a parody of music composed earlier on Italian texts.

He uses a cantus firmus on long repeated notes especially to illustrate God's speech and majesty, for example "for the mouth of the Lord has spoken it" in movement 4.

An accompagnato is based on the words of the prophet Haggai, dealing with the splendor of the temple, and of Malachi who foretold the coming messenger.

The Air for soprano, alto, or bass, as a human reaction to the words of God, shows the trembling in the expectation of the Lord's appearance twofold in a dramatic scene.

The Air begins with the pensive question "But who may abide" and continues, in a sharp shift of time and tempo "Prestissimo", with the statement "For He is like a refiner's fire".

The statement returns a final time after a rest, marked Adagio, giving the soloist the opportunity to express it in a cadenza.

Handel rewrote this dramatic scene in London in 1750 for the castrato Gaetano Guadagni, after he had initially set the text as a recitative for bass.

[10][11] After the rather general introduction, Scene 3 addresses Isaiah's specific prophecy about the virgin birth of a Messiah by expanding more verses from different chapters of the prophet.

The choir voices enter in imitation, as if gathering, but soon sing together, starting with "arise" (Isaiah 60:1) on a pronounced "ascending fourth"—a signal observed by musicologist Rudolf Steglich as a unifying motif of the oratorio.

[6] For behold, darkness shall cover the earth In stark contrast, the bass sings the continuation in an accompagnato "For behold, darkness shall cover the earth" (Isaiah 60:2–3) on a background of the strings playing mysterious repeated motifs in major and minor seconds, until the text switches to "but the Lord shall arise" (which the voice presents as a melisma of two measures), followed by coloraturas on "glory" and an upward octave leap to proclaim in the end "and kings [to the brightness of thy rising]".

The darkness is illustrated by the bass and the celli in unison, starting with the seconds of the movement before and proceeding in uneven steps, carefully marked for irregular phrasing.

In the second verse of the text, the gloom of the beginning is intensified by similar unsupported figures on "shadow of death", but once more relieved by "upon them has the light shined", again with the voice singing independently.

The words "and the government shall be upon his shoulders" appears in stately dotted rhythm, culminating in the names "Won-derful", "Coun-selor", "The Mighty God", "The Everlasting Father", "The Prince – of Peace", with the shimmering coloratura in the strings.

The movement is based on the first section of Handel's Italian cantata No, di voi non vo' fidarmi (HWV 189, July 1741),[10][11] which had "originally expressed a distinctly secular kind of joy".

He marked them as "da lontano e un poco piano" (from afar and somewhat quietly) and originally planned to place them offstage (in disparate), to create the effect of distance.

Handel's setting of the famous words is strikingly simple and effective: "Glory to God, glory to God in the highest" is sung by the high voices (soprano, alto and tenor), whereas "and peace on earth" is given to the low voices of tenor and bass in unison, with the bass dropping an octave for "on earth".

The sequence is repeated, but this time all four voices sing "glory" and "peace", the first in a high register, then low again with the bass dropping an octave.

The text is compiled from Zechariah (who saw God's providential dealings), Isaiah's oracle of salvation for Israel, and his vision of the Shepherd (seen fulfilled by the Evangelist Matthew).

Finally, a da capo seems to begin, but only the first entry of the voice is exactly the same, followed by even more varied coloraturas and embellishments to end the aria.

The Old Testament part "He shall feed His flock like a shepherd" (Isaiah 40:11), is sung by the alto in music in 12/8 time which is reminiscent of the Pifa, but moving first down, then up.

The New Testament part, in the Gospel words of Jesus, are changed to the third person "Come unto Him, all ye that labour" (Matthew 11:28–29).

Light and easy-going is the theme of a fugue, drawn from the duet for two sopranos "Quel fior che all’alba ride" (HWV 192, July 1741).