Views from the Choir Loft

Andre Mocquereau Theory of Rhythm

Jeff Ostrowski · April 15, 2026

“Gregorian Chant Isn’t a Platform for Your Personal Theories, Jeff” • (A Letter We Received)

“My desire, Leroy, is to answer your question in a rigorously straightforward way.” —Jeff Ostrowski

Jeff Ostrowski · May 5, 2025

“Basic Catechism of Gregorian Chant” • Fifteen Questions Answered

“Kids, you’re only on this floating rock for a very short time.”

Jeff Ostrowski · March 29, 2025

PDF Download • “Gloria III” Organ Accompaniment

This is surely one of music history’s great ironies!

Jeff Ostrowski · December 3, 2024

PDF Download • Pristine Scan: Father Mathias’ 1905 Kyriale Organ Accompaniment (186 pages)

Father Mathias served as organist for Strasburg Cathedral, where he founded the “Saint Leo Institute for Church Music” in 1913.

Dr. Charles Weaver · February 5, 2024

What is the Place of the Horizontal Episema in Dom Mocquereau’s Theory?

It really is a minor part of Mocquereau’s theoretical enterprise. That doesn’t mean it’s completely pointless, though.

Jeff Ostrowski · October 23, 2023

“Did One Man Single-Handedly Sabotage the Gregorian Restoration?” • (Part 2 of 2)

Will anyone step forward to defend this?

Dr. Charles Weaver · October 5, 2023

PDF Dissertation • “Dom Mocquereau and Music Theory” (282 Pages)

My thesis on how Dom Mocquereau relates to other theories of musical rhythm is now available for download.

“Reminder” — Month of April (2026)

On a daily basis, I speak to people who don’t realize we publish a free newsletter (although they’ve followed our blog for years). We have no endowment, no major donors, no savings, and refuse to run annoying ads. As a result, our mailing list is crucial to our survival. It couldn’t be easier to subscribe! Just scroll to the bottom of any blog article and enter your email address.

—Jeff Ostrowski

Simplified Accompaniment (Easter Hymn)

Number 36 in the Brébeuf Hymnal is “At the Lamb’s high feast we sing,” an English translation for Ad Cenam Agni Próvidi (which was called “Ad Régias Agni Dapes” starting 1631). As of this morning, you can download a simplified keyboard accompaniment for it. Simply click here and scroll to the bottom. Many organists are forced to serve simultaneously as both CANTOR and ACCOMPANIST. In spite of what some claim, this can be difficult—which explains why choirmasters appreciate these simplified keyboard accompaniments. Sadly, many readers will click that link but forget to scroll to the bottom where the simplified PDF file is located.

—Jeff Ostrowski

PDF Download • “Quasi Modo Sunday”

The Introit for “Quasi Modo Sunday” (12 April 2026) is particularly beautiful. The musical score can be downloaded as a PDF file, and so can the organ accompaniment. The official language of the Catholic Church is Latin (whereas Greek is our mother tongue). Vatican II said Gregorian Chant must be given “first place” under normal circumstances. As a result, some parishes will rightly sing the authentic version. On the other hand, because so many USA dioceses disobey the mandate of Vatican II, some musicians sing plainsong in the vernacular. I have attempted to simultaneously accompany myself on the pipe organ while singing the English version. Although very few take advantage of it, the complete Proprium Missae is posted at the flourishing feasts website.

—Jeff Ostrowski

PDF Download • “Anima Christi”

I received a request for an organ accompaniment I created way back in 2007 for the “Anima Christi” Gregorian Chant. You can download this PDF file which has the score in plainsong followed by a keyboard accompaniment. Many melodies have been paired with “Anima Christi” over the centuries, but this is—perhaps—the most common one.

—Jeff Ostrowski

PDF • “Liturgical Law” (467 Pages)

On Good Friday during the middle ages, the pope privately recited THE ENTIRE PSALTER. If you don’t believe me, see for yourself by reading this passage by Dom Charles Augustine Bachofen (d. 1943). His famous book—called “Liturgical Law: A Handbook Of The Roman Liturgy”—was published by the Benjamin Herder Book Company, which was the American arm (operating out of St. Louis, Missouri) of one of the world’s most significant Catholic publishers. Dom Charles Augustine Bachofen was born in Switzerland but spent his career between the Benedictine monasteries at Conception (Missouri) and Mount Angel (Oregon). His 1931 masterpiece, Liturgical Law can be downloaded as a PDF file … 467 pages!

—Jeff Ostrowski

“Gregorian Chant Quiz” • 24 March 2026

How well do you know your Gregorian hymns? Do you recognize the tune inserted into the bass line on this score? For many years, we sang the entire Mass in Gregorian chant—and I mean everything. As a result, it would be difficult to find a Gregorian hymn I don’t recognize instantly. Only decades later did I realize (with sadness) that this skill cannot be ‘monetized’… This particular melody is used for a very famous Gregorian hymn, printed in the LIBER USUALIS. Do you recognize it? Send me an email with the correct words, and I promise to tell everybody I meet about your prowess!

—Jeff Ostrowski