Henri Potiron is perhaps unduly maligned or forgotten, depending on your perspective. He served at the basilica of Sacré-Cœur as maître de chapelle and, at the very end of his career, as « organiste titulaire accompagnateur »; I suspect that his retirement was indeed well-deserved, but he left right as the changes started to happen. Anyway, he also had a long teaching career, and he was something of an expert, for his time, on modality, which is fascinating given that his written accompaniment is more late Romantic than anything else. (More here, in French, from an article written some time ago, at the appointment of the two titular orgaanists, Philippe Brandeis and Gabriel Marghieri, as co-titular organists of the basilica).

I was looking for something in the Graduel paroissial containing the accompaniment of Potiron, and I thought that this extract of the introduction was worthwhile. Potiron worked closely with Solesmes and its daughter houses; he regrets that, unlike with his Kyriale, he was unable to work with Dom Jean-Hébert Desrocquettes, who was at this point at Quarr Abbey on the Isle of Wight. So naturally, we already know that he is going to use the ictus etc.

If truth be told, and without any doubt, it would be better to not accompany Gregorian chant. Historically, it's obvious, but also aesthetically, that accompaniment nearly always harms the execution (I set aside the case, too frequently occurring unfortunately, of choirs which have an absolute need to be supported by the organ). It frustrates the rhythm and the delicateness of the details. It brings in its harmonies a formidable synthesis and precision, while the melody often takes pleasure in reticence and equivocation, which give to it in part its true character, the harmonic translation being thusly a kind of treason; the harmony itself, frustrated in a role which was not made for it, loses in this its musicality and its elegance.

However, since chant is chanted almost nowhere a capella, accompaniments written with some reflection are preferable to the improvisations of the organist, even skillful and musical…

This sentiment is, for many of us, shared, i.e. it is preferable to not have any accompaniment, although this changes at the end; the preference today seems to be for improvisation or at least playing from markings on your own copy of the square notation over playing from modern notation with everything written out.

The style is quite interesting: although it is heavier than the Fontgombault style, and that of Dom Desrocquettes himself, Potiron believes that his are not much loaded with chords… which is debatable, even as I have a soft spot for this sort of grand French style as much as I do for the Fontgombault style with hardly any movement and an 8' flute and not much more. Potiron intended for these to be played on manuals or on organs with pedals, and if need be one can transpose with the automatic transposer, but "thank God" that, in his day, there were musicians who could still transpose.

He concludes that "one will never forget that the accompaniment must be very discrete." I believe that we can agree about that, although we won't agree on the actual meaning of "discrete"!