By the mid-13th century, these three basic notational shapes for single notes acquired
temporal significance, the virga becoming a long, the punctum a breve, and the rhomboid
a semibreve, the ancestor of the modern whole note.
Two or more notes linked in the same figure drawn without lifting of the pen comprise
a “ligature,” a feature of musical notation retained through the 16th century. Ligatures
were for melismatic music, that is, melodic lines without text (sine littera notation). If a
text were given to such a melodic line, the ligatures would be broken up to allow the
association of pitches with syllables (cum littera notation).
The interpretation of a piece of music preserved in square notation may vary according
to its genre, the date at which it was written, and its geographical or cultural point of
origin. Modal notation, which originated probably within the Notre-Dame School,
organized ligatures into configurations that graphically represented patterns known as
“rhythmic modes,” a continuous stream of long and short notes. In order to notate more
complex rhythms in modal notation, extant sources indicate numerous changes and
refinements, some that died out and some that gradually led to a more reliable style of
notation, called Franconian after its primary spokesperson, Franco of Cologne. Franco’s
description of this new notation, the Ars cantus mensurabilis (ca. 1280), had such
authority and wide circulation that it contributed greatly to a notational standardization by
which any piece of rhythmic music could be read, not only in the Parisian circles in
which these notations and genres arose but throughout western Europe.
Franconian notation, the earliest true mensural notation, established distinctive graphic
elements denoting specific rhythmic values that could either stand in place of a unit
within a mode or stand alone and always, unequivocally indicate the same rhythm, both
in texted and in melismatic music. Franconian rhythm depends upon equal pulses, each
the value of the perfect long, which then could be subdivided in a variety of ways. In
succeeding composition, notation, and theory, ever smaller note values were grouped in
different ways and in different numbers, always subdividing the equal pulses of the larger
note values. Petronian notation (after Pierre de la Croix), which seems to have succeeded
Franconian quickly, primarily describes the division of the breve into as many as seven
semibreves. To give an idea of the extent to which this process affected western music,
by the 16th century it was the semibreve, or tactus, that had become the measure of this
equal pulse, which was divisible by minims, semiminims, and fusae, known today as half,
quarter, and eighth notes.
In Petronian notation, the rhythmic values of the fast semibreves, all equivalent in
appearance, were resolved according to certain rules. In France, further revision of
Franco’s system in the early 14th century resolved the ambiguities of Petronian notation
and at the same time allowed for an enormous flexibility in the notation of rhythm. This
Ars Nova notation is usually associated with Philippe de Vitry and Jehan des Murs. By
means of an additional symbol, the minim (an ascending stem was added to the rhomboid
shape of the semibreve), short note values could be indicated precisely and
unambiguously. With the admission of duple meter and the rational organization of the
entire notational system, the exploitation of the new rhythmic possibilities became a
preoccupation of 14th-century composers. The “classic” state of Ars Nova notation,
represented in the musical works of Philippe de Vitry and Guillaume de Machaut and in
the theoretical treatises of Jehan des Murs, began to expand in the course of the 1370s.
Medieval france: an encyclopedia 1230