Organum: Alleluia Justus ut palma
Norton Recorded Anthology of Western Music, CD 1 Track 30
The first example of counterpoint in our survey is a modest one. We have heard some harmony in vocal pieces supported by instruments as well as the purely instrumental passages in the preceding tracks. We have even encountered brief moments of counterpoint during a few improvisational flourishes. But this organum provides us with our first carefully crafted counterpoint. Much of the piece, however, is unadorned plainchant. The harmonized phrases serve to contrast the sections of monody.
This reminds me of track 20 where, for dramatic purpose, a 10th century trope uses contrasting voice registers. Regarding this organum, even though the contrasts do not seem to support the meaning of the text, they lend a shape to the piece that engages the listener. The repeat of the opening phrases that we hear in this recording also helps the listener as it signals the conclusion of the piece. (On the topic of conclusions, we should note that, in this survey, the cadence of a sixth to an octave first appears here.)
What I like about this piece is the counterpoint of the first Alleluia
. The general direction of the two lines is to hesitantly move from an octave to a unison. When the unison is first achieved the upper voice crosses under and then returns to the unison. All at once this voice crossing emphasizes their unison, creates harmony, and briefly touches an unexpected change in timbre.