in memory of Dr. Jan van Biezen, 1927–2021


Proper of the Mass for Sundays and Feasts in Proportional Rhythm

Thirteen Offertory Chants (with verses); includes both Gregorian and modern notation for each chant

Rudiments of Gregorian Chant in proportional rhythm (PDF); for a similar introduction to the Solesmes method, see “Fundamentals of Gregorian Chant” below

Chant recordings sung in proportional rhythm according to the oldest extant manuscripts (YouTube)

(new 10/19/23) The Value of Laon 239

Chant Glossary (CCWatershed)

“Gregorian Rhythm Wars" Exchange at CCWatershed

Table of Neumes (PDF) - including Metz, St. Gall, Vatican, neography, and modern notations with a summary of principal differences between proportional rhythm and the Solesmes method

Tables for Neumes Other than Metz (Laon) and St. Gall (

Table of Neumatic Elements (PDF); one-page, Gregorian notation without rhythmic markings

Rearticulation and Upper Auxiliary Notes (PDF)

Written Evidence for the Decline and Loss of the Authentic Traditional Rhythm

Who's Who in Gregorian Chant

Editorial Principles

Discussion of Cardine’s “Is Gregorian Chant Measured Music?”


“King James Only" Catholics

Rhythmic Analysis of the Introit Dominus Dixit (PDF)

Critique of the Solesmes Edition of the Offertory Oravi Deum (PDF); includes side-by-side rhythmic comparison in both modern and Gregorian notation

Recommended Reading:

Excerpt from Gregorian Chant according to the Manuscripts by Dom Gregory Murray, O.S.B. (full PDF here)

Summary of “The Rhythm of Gregorian Chant” from Rhythm, Meter and Tempo in Gregorian Chant by Dr. Jan van Biezen; the examples in square notation are available here

Further Reading:

Tradition of Durational Values in Gregorian Chant" by Arthur Angie (in The Caecilia, 1934, vol. 60, no. 10–11)

Collected Articles on Chant Rhythm by Dom Gregory Murray, O.S.B.

Gregorian Chant: A History of the Controversy Concerning Its Rhythm by John Rayburn

Rhythmic Proportions in Early Medieval Ecclesiastical Chant by Fr. Jan Vollaerts, S.J.


Mensuralism & Historically Informed Performance Practice:


Note: Most if not all of the following sites presuppose a “nuanced," non-proportional rhythmic interpretation.

Restored Editions:

Neumed Editions without Melodic Corrections:

Solesmes Method & Editions:

mnemonic for ictus placement: 1's 1 (vertical episema), 2's double (beginning of doubled or tripled note), 3's a group (beginning of a group), 4's full (full or double bar line)

PDF Libraries:

Church Regulations concerning Chant Editions:






Patrick Williams: organistAL at aol dot com