Music from the Earliest Notations to the Sixteenth Century

In every talea, then, six breves’ worth of musical time is organized by perfect longs (that is, in
“perfect minor modus”), requiring the use of red ink. It is here, of course, at the tenor’s friskiest moment,
that the hockets appear in the texted parts. Their rhythms, like the rhythm of the tenor, are the same each
time. After three taleae, the note values are halved to coincide with the second cursus of the color, so that
the tenor proceeds twice as “fast,” and the red notes denote six semibreves’ worth of time organized in
perfect tempus. The frisky tempus shift becomes much friskier, since the perfect breve that now begins the
red-ink patch crosscuts the basic tempus unit, producing a true syncopation—something that had never
before been possible in notated music. Needless to say, the hockets in the upper parts get friskier, too; and
again these puckish rhythms reappear each time the tenor syncopation returns. This passage introduces
what was a permanent stylistic acquisition for fourteenth-and fifteenth-century music. “Coloration” (the
use of a contrasting ink color, or, later, the filling in of notes ordinarily left “white”) became a standard
way of changing tempus in midstream to produce fascinating rhythms.

ISORHYTHM