Gordon Archbold Slater D.Mus. FRCO (1896–1979) was an English cathedral organist, who served in Leicester Cathedral and Lincoln Cathedral. He was a composer of organ, piano and choral music. Three hymn tunes appear in well-known and well-used books. The famous of which, 'St Botolph' is very widely sung to the words "Jesu the Very Thought of Thee".
"Canticle on 'St. Fulbert'" was published by Novello in 1956. It is the first piece in the Easter volume of "Festal Voluntaries." It is a "big piece," despite it's relative brevity.
For those not familiar with the word, a "canticle" is a hymn, psalm or other song of praise taken from biblical or holy texts other than the Psalms. Since Slater's work is based on a hymn, I'm not really sure, why he called this a canticle, but I guess the name looks and sounds good!
The work is based upon the well-known melody, "St. Fulbert," composed by Henry J. Gauntlett (1805-1876), who is most famous for his Christmas hymn, "Irby" (Once, in royal David's city."
The text, "Chorus novae Jerusalem," is attributed to St. Fulbert (c. 960-1028), and the original translation was done by Robert Campbell (1814-1868), but I think the "usual version" of the text is the one done by John Mason Neale (1818-1866).
The work is dedicated to Healey Willan (1880-1968), an important English organist who made most of his career in Canada.
The music is massive in it's impact and dense to play. The counterpoint is constant, and goes from start to end. The effect strikes me as something almost "neo Baroque," but the harmony and style is purely 1950's English cathedral at it's best.
Since the melody may be unfamiliar to many, I played it through on the tuba, immediately before the piece.
Photos of Slater, Willan, Neale, and Lincoln Cathedral, where Slater was organist when he wrote this, are attached below. You'll find few cathedrals as magnificent as Lincoln!
For those interested in the splendid words, the full text is given in First Comment.