Occasionally I need to fill a gap in our repertoire, and because I am an organ maximalist (and our congregation happily sings, but does so much more confidently with organ), I wind up needing accompaniments. Or I don't like what I can find or what the organist has. I noticed that the Liber Cantualis Comitante Organo style really allows a congregation (monastic choir, etc.) to sing above the melody, even if the organist still provides it. So our already-strong congregation got that much stronger when we switched to the LCCO version (apparently the organist just needed the doxology written out, which I was happy to do). Ditto for the Marian antiphons…

The Asperges ad lib I is cribbed from Portier. We don't actually use that, but I figured that someone might use it; we do use the Asperges ad lib II in Advent and from Septuagesima through Palm Sunday. The others are my own. We'll be switching to these melodies for Benediction in Advent for the first time, and hopefully we'll do the same in Lent as well. (We normally use O Salutaris in mode 7 and the Tantum "cantus modernus" on ordinary Sundays; the Corpus Christi melodies on feasts; in Paschal Time, the O Salutaris set to the Pentecost Lauds melody with the attached Tantum IX with the melody of Urbs beata Jerusalem; on weekdays per annum and after Septuagesima, DUGUET and ST THOMAS, which get old kind of fast…and since a bunch of local parishes use DUGUET or especially WERNER and then the mode III chant even on weekdays, I don't feel obliged to use these year-round on weekdays.)

I don't have really any theory training; everything is from observation and making something out of Eugène Lapierre's summary of the classical Solesmes accompaniment style learned from Dom Desrocquettes and what Fr. Bachmann sent me, so my strategy is to change the bass note on the ictic note (I also avoid abbé Portier's eighth notes particularly in the alto line to keep things easier); use 1-3-5 chords, 1-2-4, open fifths (the most common, but you get 1-3, 1-4, and 1-6 too), and more rarely variations like 1-4-6 (or 1-3-6 even…). When in doubt, go to D minor no matter the mode (and ultimately the key signature). You can also use the relative minor scale (e.g. use the first inversion of A minor when there are no sharps or flats in the key signature). Avoid second inversion (see my problem above). As I said, my theory knowledge is severly lacking, so I just don't mess with sevenths.

In the Tantum VI, I'm not sure that I really like the final chords of the verse and in A- of "Amen; the very last part, the -men of "Amen", behaves correctly — I would just need to change the notes if I change the chord at the end of the verse.

I have reduced, as far as I can tell, the number of parallel fifths and octaves, at least trying to avoid them between the outer lines, which is prohibited in this style. However, in Tantum IX, there are, at "cernui" and "-tum no-", "ritui", and "defectui" some potential problems. Some feedback would be welcome. The keys are chosen between what I can glean from Fontgombault's (or the ICRRSP's) recordings and then what works with my voice, since I can kind of guess what the schola, and the congregation, can handle.

(I'll leave the tag as is, since anything fits under it; I don't think that these are really "new compositions" exactly…)