A Dictionary of Music and Musicians/Musica Mensurata
MUSICA MENSURATA or Cantus Mensurabilis (Measured Music). The notes of Plain Chaunt were originally of equal length; or, at least, were only lengthened or shortened indefinitely, in accordance with the accent of the words to which they were adapted. But, after the invention of Figured Music, it became necessary to design a system of Notation capable of expressing the relative duration, as well as the pitch, of every note intended to be sung; and thus arose a new species of Song, called Cantut mensurabilis, or Measured Music.
One of the earliest known writers on this subject was the celebrated Franco of Cologne, who, upon the strength of his Tract, entitled Ars cantus mensurabilis, written during the later half of the 11th century, has frequently been credited with the invention of the Time-Table. It is but fair however, to say, that, in this very Tract, Magister Franco himself speaks of 'many others, both recent, and antient,' (multos tam novos quarti antiquos), who have written on the same subject; whence, notwithstanding the testimony of Marchetto de Padova, who wrote two centuries later, we must infer that we are indebted to our author rather for a compendium of what was already known at the time when he flourished, than for a new or original discovery. In confirmation of this view, Coussemaker, in his 'Scriptores de musica medii ævi,' cites several MSS. which appear to be of earlier date than the Treatise of Franco; and prints, in extenso, examples which set forth systems far less completely developed than that which Franco describes.
Next, in point of antiquity, to Franco's Treatise, is one written by our own countryman, Walter Odington, of Evesham, in the year 1220. Others follow, by Marchetto de Padova, in 1274; Johannes de Muris, in 1321; Robert de Handlo—another Englishman—in 1326; Prodoscimus de Beldomandis, in 1410; Franchinus Gafurius, in 1480; and numerous other authors, who all concur in representing Franco as an authority entitled to the utmost possible veneration.
A detailed analysis of these interesting works would far exceed the limits of the present Article. The systems they set forth are, of course, progressive; and a sufficiently explicit summary of their successive stages of development will be found in the Articles Notation, Time-Table, and others therein mentioned.