I can vaguely recall marveling at this communion chant for the epiphany last year, but somehow this year it has taken on an especially remarkable meaning. It is surely the most "foreign" sounding communion antiphon in the Church year. You know from the first notes that there is a mysterious search going on, and then from the second phrase with Stellam that we are looking up at the stars.
But the really interesting part takes place on the Oriente. Here we have the figure: Fa Sol La Ti Sol La Mi. Jeffrey Ostrowski pointed out to me that we have a tritone here, three successive whole notes -- the very sound of something approaching dissonance. I can imagine that a new schola, unused to modality, would be rather taken aback by this phrase.
Now, either the composer knew what Eastern music sounded like or knew how to signify the sound in music, but in either case, there is no mistaking what is being conveyed here. Even without words, you are being told a story of people on a journey looking at stars, coming from faraway lands and headed somewhere.
Many Mode IV chants sound to me like incomplete Mode I chants but here we find an archetype of a chant centered on Mi as its final. But the ear doesn't quite find it until near the end. On "Adorare Domimun" you are given a nice preparation and then placed comfortably at home on the last note, which is now indisputably the note around which the whole chant centers. You know you have arrived, and those on the journey have arrived too at their destination.
Isn't it remarkable how this small this piece can convey all that information? It is utterly and completely masterful.
Now, a quick performance note. In this piece we have three occurrences of the Salicus. It looks like a punctum attached to a podatus with an ictus on the lower note. In fact, it is a completely different figure called the Salicus.
That seeming ictus is the only place in chant that occurs the vertical episema, and it requires that the second note be expressively warmed as you move through the phrase. The salicus on Oriente is absolutely essential to making this chant achieve its full effect.
I point this out only because this is one of the stumbling blocks for new scholas. Hardly a surprise: David Hiley says its "nature is puzzling." I think we had been singing for two years before we came to understand this point. Now our chant director marks each salicus so that we won't run over them.
For further insight we turn to Dom Johner:
The first phrase moves joyously. The second breathes the spirit of adoration. Only with venimus do we perceive an echo of the joy of the first phrase. For the closing formula of the first phrase the cadence of the psalm tone of the fourth mode, b g e, served as a model. The tritone over Oriente--not so "very disturbing since a twofold b has preceded it heightens the peculiar, one might almost say the Oriental, effect of this passage. In three words the unaccented "i" of the second last syllable regularly receives melodic prominence. The fact that the common people accented the Latin language differently from the learned class may be the cause of this; without a doubt plain song was influenced considerably by this so-called "vulgar" Latin.
