Medieval Manuscript Monks Singing

Jeff Ostrowski · February 27, 2026

PDF Download • “Funerals in the Ordinary Form”

Many have requested the following document (which governs any funerals at my parish).

In 1905, when the Vatican Commission on Gregorian Chant began publishing the EDITIO VATICANA—still the Church’s official edition— they assigned different Masses to different types of feasts. However, they were careful to add a note (which began with the words “Qualislibet cantus hujus Ordinarii…”) making clear “chants from one Mass may be used together with those from others.” Sadly, I sometimes worked for TLM priests who weren’t fluent in Latin. As a result, they stubbornly insisted Mass settings were ‘assigned’ to different feasts and seasons (which is false). To understand the great variety, one should examine the 1904 KYRIALE of Dr. Peter Wagner. One should also look through Dom Mocquereau’s Liber Usualis (1904), in which the Masses are all mixed up. For instance, Gloria II in his book ended up being moved to the ‘ad libitum’ appendix in the EDITIO VATICANA.

—Jeff Ostrowski

Like! Like! Like!

You won’t believe who recently gave us a “like” on the Corpus Christi Watershed FACEBOOK PAGE. Click here (PDF) to see who it was. We were not only sincerely honored, we were utterly flabbergasted. This was truly a resounding endorsement and unmistakable stamp of approval.

—Jeff Ostrowski

PDF Download • “Atténde Dómine”

Although it isn’t nearly as ancient as other hymns in the plainsong repertoire, Atténde Dómine, et miserére, quía peccávimus tíbi (“Look down, O Lord, and have mercy, for we have sinned against Thee”) has become one of the most popular hymns for LENT—perhaps because it was included in the famous Liber Usualis of Solesmes. This musical score (PDF file) has an incredibly accurate version in English, as well as a nice version in Spanish, and also the original Latin. Although I don’t claim to have a great singing voice, this morning I recorded this rehearsal video.

—Jeff Ostrowski

Extreme Unction

Those who search Google for “CCCC MS 079” will discover high resolution images of a medieval Pontificale (“Cambridge, Corpus Christi College, MS 079”). One of the pages contains this absolutely gorgeous depiction of the Sacrament of Extreme Unction.

—Corpus Christi Watershed

PDF Chart • “Plainsong Rhythm”

I will go to my grave without understanding the lack of curiosity so many people have about the rhythmic modifications made by Dom André Mocquereau. For example, how can someone examine this single sheet comparison chart and at a minimum not be curious about the differences? Dom Mocquereau basically creates a LONG-SHORT LONG-SHORT rhythmic pattern—in spite of enormous and overwhelming manuscript evidence to the contrary. That’s why some scholars referred to his method as “Neo-Mensuralist” or “Neo-Mensuralism.”

—Jeff Ostrowski

PDF • “O Come All Ye Faithful” (Simplified)

I admire the harmonization of “Adeste Fideles” by David Willcocks (d. 2015), who served as director of the Royal College of Music (London, England). In 2025, I was challenged to create a simplified arrangement for organists incapable of playing the authentic version at tempo. The result was this simplified keyboard arrangement (PDF download) based on the David Willcocks version of “O Come All Ye Faithful.” Feel free to play through it and let me know what you think.

—Jeff Ostrowski