HOSE WHO ACCOMPANY Gregorian melodies on the organ must have a sensitive ear and understand where to place dissonance. A common misconception goes something like this: “I don’t want dissonance in my accompaniments, so I don’t change chords very often.” Nothing could be further from the truth! Organists who change chords infrequently (and lack familiarity with voice-leading techniques) create horrific dissonance without realizing it.
Warning! Warning! Musician about to express opinions—Proceed with caution and coffee.
Consider the following example by Henri Potiron. Are your ears sensitive enough to hear the ill-considered (in my humble opinion) dissonances Potiron created highlighted in pink? The third “pink” is especially egregious:
The areas highlighted in yellow are also ill-conceived (in my humble opinion), and expose open chords and ugly fourths. In general, Potiron loiters on chords too long, then abruptly moves to another chord with motion in all the voices—and that’s not cool. In too many places he misses opportunities to help keep the melody flowing. The way all voices move in the same direction at the beginning of “amícti” is faulty, and the 6/4 chord for “Amen” is bizarre, forbidden, and lazy. It’s as if Potiron fell asleep at the wheel.
Finally, the voice-leading would be less jagged if he moved to D quicker on “Príncipi” (cf. suggested note in red ink).
This book in question, 1948 Daily Hymnal, has an IMPRIMATUR from the Archbishop of Westminster, and uses accompaniments by Potiron exclusively (if memory serves). Monsieur Henri Potiron was—as many readers know—the most famous exponent of the “Solesmes” method of Gregorian accompaniment. His title was Maître de Chapelle de la Basilique du Sacré Cœur et Professeur a l’Institut Grégorien.