The Canadian Encyclopedia says this about the "early" organ works of Healey Willan (1880-1968): With the music for organ one enters a different world. Here Willan was thoroughly at home and made a significant and lasting contribution. One work stands out: the monumental "Introduction, Passacaglia and Fugue" of 1916. The Preludes and Fugues in C minor and B minor and the "Epilogue" are the other major works from this period. While not exploring the possibilities of the instrument as searchingly as his masterpiece, they are idiomatic and very typical of their time. They combine an innate Englishness (with a Stanfordian flavor) and a European chromaticism that can be found in Reger and Karg-Elert.
Born in England, Willan became organist-choirmaster of Toronto's largest church, St. Paul's, Bloor Street, but it was his royalties as a composer which allowed him to leave "low church" St. Paul's in 1921 and to become Precentor of the Church of St. Mary Magdalene (Toronto).
The prelude on "Quem pastores" comes from "Six Chorale Preludes" published by Concordia Publishing House in 1950. This is the first piece of the first set, of which there are sic.
"Quem pastores" (He who the shepherds prasied) is a 16th century German carol. The earliest sources of the carol are from the fifteenth century, including the Hohenfurth Monastery Ms. 28 (1410). Many versions exist from the sixteenth century. The most famous version is from Michael Praetorius, Musae Sioniae (1607), with the German text "Den die Hirten lobeten sehre."
The version that Willan used is SLIGHTLY different from the most usual version of the tune, but the "more popular" version is given as well, and other will work perfectly with the piece as it is written. :-)
In listening, perhaps the 32' Sub Bass was a bit much at the end, but, you know my weakness for this sort of thing.
The score is attached below, as well as a "different" photo of Healey Willan.