The last word from the ancient sources will be given here to Johannes de Grocheo, a theorist
who lived around the year 1300AD in Paris.
Latin: Der Musiktraktat des Johannes de Grocheo ..., by Ernst Rohloff
Media latinitas musica, vol. 2, Leipzig, 1943, p47
De Grocheo contrasts 'measurable' conductus and motet with 'immeasurable' or 'plain' chant
of Gregory the Great. In modern terms, we might call this the difference between regular
barring (such as contiguous 3/4 or contiguous 4/4) and irregular barring or having no barring
at all. De Grocheo is seemingly discussing 'dividing music' into groups of notes, rather than
dividing notes themselves. He echoes Guido d'Arezzo in using the term 'parts of music'.
'Part' is a term applicable to metrical poetry but it was also used to refer to groups of notes
but not individual notes (which were described only by the word 'syllable'). Through Guido,
we know that having different sizes of 'parts' distinguished 'quasi prosaici cantus' (as though
prosaic song) from 'metricos cantus' (metric song).
It is reasonable to suggest that the notion of minute lengthenings or shortenings of long and
short notes was not even a structural concept for de Grocheo in relation to the notion of
musical divisions, for he assures the reader of rules of measure existing in all music and,
moreover, he cannot allow the concept of a form of music which is not measured in any
manner, which would seem to exclude the concepts of oratorical or free rhythm from his
Others, however, divide music into plain or
immeasurable and measurable, by 'plain' or
'immeasurable' understanding 'ecclesiastic',
which, following Gregory, is fixed with many [lit.
more] tones. By measurable they understand
that which is made out of diverse sounds at the
same time measured and sounding, as in
conductuses and motets.
But, if by measurable they understand music
[as being] in no manner measured, indeed
sung completely as wished / indeed in
what has been willingly said, they are
completely deficient, for whatever performance
of music - and of whichever art - should be
measured by the rules of that art. If however
by immeasurable they understand 'not too
precisely measured', this division, as seen, can
In whatever way, therefore, one divides music,
let it be said thus.
For us, it is truly not easy to divide music
correctly, because, in good division, the
dividing members should empty out the whole
natural order/substance of the whole divided
thing. However, many are the parts of music,
and diverse, following diverse usages or
diverse languages in cities or in diverse
Alii autem musicam dividunt in planam
sive immensurabilem et mensurabilem,
per planam sive immensurabilem
intellegentes ecclesiasticam, quae
secundum Gregorium pluribus tonis
determinatur. Per mensurabilem
intellegunt illam, quae ex diversis sonis
simul mensuratis et sonantibus efficitur,
sicut in conductibus et motetis.
Sed si per immensurabilem intellegant
musicam nullo modo mensuratam, immo
totaliter ad libitum dictam, deficiunt,
eo quod quaelibet operatio musicae et
cuiuslibet artis debet illius artis regulis
mensurari. Si autem per immensurabilem
non ita praecise mensuratam intellegant,
potest, ut videtur, ista divisio remanere.
Quomodo igitur quidam dividunt
musicam, sic sit dictum.
Nobis vero non est facile musicam
dividere recte, eo quod in recta divisione
membra dividentia debent totam naturam
totius divisi evacuare. Partes autem
musicae plures sunt et diversae
secundum diversos usus, diversa
idiomata vel diversas linguas in
civitatibus vel regionibus diversis.