Parallel, Oblique, and Contrary Motion

Album: Leonin & Perotin: Sacred Music from the Notre Dame Cathedral
Track: "Viderunt Omnes" (Tracks #2 - 8)
Composer: Léonin
Instruments: 2 voices
Musical Form: Conductus
Year: ~1150

Following "Beata Viscera", the album Leonin & Perotin: Sacred Music from the Notre Dame Cathedral takes a purposeful step backwards and presents the first of five renditions of an ancient Christmas chant, Viderunt Omnes (meaning "all have seen"). Written by an unknown medieval composer, the first arrangement demonstrates polyphony in its simplest form. To begin the piece, we hear only a single voice performing a traditional Gregorian chant, a chant not unlike the ones reviewed in my second entry. After only a minute of this, however, we hear a another voice arise, moving in parallel motion above the first and adding texture that must have been thrilling to the medieval ear (listen to an example of parallel motion). Not impressed? Of course you're not, modern music is replete with harmonies much more complex than this one, but be patient.

Continuing to the next track, we hear the first contribution from Léonin and the beginning of the second rendition of Viderunt Omnes, this time split into five sections. Léonin preceded Pérotin by ~50 years and most of his compositions had only two voices, but his work helped lay the foundation for the more complex four-voice motets that would follow. In addition to experimenting with parallel, oblique, and contrary motion in the vocal parts, he also was among the first composers to use rhythmic modes, a set of very simple rhythms common to later medieval music. In this third track, he demonstrates a mastery of oblique motion; that is, the motion of one voice over the constant or slowly changing pitch of another (listen to an example).

Léonin works with a mix of parallel and oblique motion through the next few sections of the piece, until we reach "Dominus." Here, he begins to experiment with contrary motion in the voices, one moving up in pitch as the other moves down (listen to an example). This technique, which was developed by the Notre Dame School of Polyphony, would later be formalized into a system of "counterpoint" and would be mastered in the early 18th century by none other than Johann Sebastian Bach. At this point, however, we only hear a glimmer of the complexity exhibited in Bach's much later work. The lower voice in "Dominus" exhibits a slow, deliberate motion, while the upper voice moves with relative freedom through the musical space carved out by Léonin. The combined effect is worth more than the sum of its parts.

External Links: YouTube