Iowa native Reber Clark (b. 1955) has made his name as a trumpeter, composer, and arranger in many different musical genres.  He set the traditional French Hymn of St. James for band sometime before 1998 as a pet project.  According to Clark:

Hymn of St. James is a composition for band based on the hymn, “Let All Mortal Flesh Keep Silence” from the Liturgy of St. James (4th Century) translated from Greek to English by Gerard Moultrie, 1864, which is set to a traditional 17th century French carol melody.

Over the years, many people have asked me about the origin of this work.  I was raised in the Episcopal Church and this was one of a very few hymns that fascinated me from a very early age.  The melody always haunted me and, having the opportunity to write a piece completely unfettered by money or time constraints, I decided to utilize this childhood memory.

The setting depicts the words of each verse of the hymn. The melody is played in its entirety four times and is descriptive of the hymn’s four verses.
The two-bar marimba solo at the beginning represents silence.
The first time the melody is played it is descriptive of the hymn’s first verse.  The strong tertian first statement is concrete and straightforward as the first verse is strong and firm in its faith.
The tonal ambiguity of the second statement suggest (sic) the paradoxical, mysterious poetry of the second verse: “King of kings, yet born of Mary”, “Lord of lords in human vesture”, etc.
The militaristic style of the third statement describes the “host of heaven” and at Circle 94 the cluster that fades in an A major chord coincides with the lyric: “as the darkness clears away.”
The fourth, and last , statement’s attempt at a “celestial” quality coincides with the fourths (sic) verse’s celestial descriptions.
The key of the original hymn is D minor, or possibly D aeolian, but six measures from the end a D major chord was chosen to signify the inevitability of good. Tritones, 6 before the end, question all that has come before, with a final answer given on the final D major eighth note.

Watch Peter Boonshaft and the Austin All-City Band play Hymn of St. James.  For some comic relief, listen to the audience comments as it goes on:

The choir version as sung by the choir at Kings College, Cambridge:

Read up on Clark’s band setting of Hymn of St. James at C. Alan Publications and Reber Clark’s blog  You can find out more about the original hymn at the Center for Church Music.  The version of the lyrics that Clark used are as follows:

Let all mortal flesh keep silence,
And with fear and trembling stand;
Ponder nothing earthly minded,
For with blessing in His hand,
Christ our God to earth descendeth,
Our full homage to demand.

King of kings, yet born of Mary,
As of old on earth He stood,
Lord of lords, in human vesture,
In the body and the blood;
He will give to all the faithful
His own self for heavenly food.

Rank on rank the host of heaven
Spreads its vanguard on the way,
As the Light of light descendeth
From the realms of endless day,
That the powers of hell may vanish
As the darkness clears away.

At His feet the six wingèd seraph,
Cherubim with sleepless eye,
Veil their faces to the presence,
As with ceaseless voice they cry:
Alleluia, Alleluia
Alleluia, Lord Most High!

Reber Clark has a bio at C. Alan Publications, a website devoted to his music, and a blog which is mostly devoted to his thoughts about new movies.