Tempus antiquorum

Only rarely do we read hints that chant may have been rhythmically differentiated, and
only in two instances are there remarks about the choir singing in strict proportional
rhythms.  Sometimes silence may speak volumes, but an
argumentum ex silentio is weak
for all that.
                                                               Gregorian chant (2009), David Hiley, p185

Is it true that only rare hints and an
argumentum ex silencio support the use of proportional
durations in Latin chant? Or is it rather the case that there are only rare (and condemnatory)
descriptions of rhythmic nuancing and an
argumentum ex silencio supporting that instead?

In relation to the song of the Latin rites, the existence of a 2:1 ratio between long notes and
short notes is clearly documented as far back the 4th century, passing through different eras
such as that of the rhythmic modes (12th-13th century).  Contrarily, no texts survive from the
1st millenium which advocate so unambiguously any practice involving 'rhythmic nuancing' or
freely irregular note durations.

St Augustine of Hippo (354-430AD) describes the ratio linking the durations of the short and
long syllables used in classical poetry in his treatise
De musica.

De Musica, book II, chapter III

In his
Tractatus de musica, datable to between 1272 and 1304, Jerome of Moravia describes
the musical values of the notation used for the rhythmic modes (the triple time method used
for singing chant in his day), relating those values to what he considered to be the musical
values of ancient times.

He states that
one 'breve' (short) or 'tempus modernorum' (time of the moderns)  - the
basic duration of the rhythmic modes, something akin to a dotted crotchet - equals
tempora antiquorum' (times of the ancients).

He also states that
one 'instantia modernorum' (instant of the moderns) - something akin
to a quaver - equals
one 'tempus antiquorum' (time of the ancients) and that this value is
indivisible in eclessiastical chant according to both the ancients and the moderns.

The Ambrosian hymn
Deus creator omnium, one of the oldest in the Latin rite, was
composed in iambic dimeter, an ancient triple time metre.  Following Jerome, we could
describe the basic
iamb (one short and one long) of Deus creator omnium as equalling
the duration of
three 'tempora antiquorum'.
Master: It is not absurd therefore that the
ancients called this, as it were, minimum of
space in time which a
short syllable has
tempus: that is to say, we progress
short to long.
Pupil: It is true.
Master: It follows then (as you also observe
that), since, just as in numbers, the first
progression is from
one to two, so in
syllables, whereby you may be sure we
progress from a
short syllable to a long
syllable, the
long must have a double time:
and, accordingly, if the space that a
occupies is correctly called one tempus,
the space that a
long occupies is also to be
named correctly
two tempora.
M. Non absurde igitur hoc in tempore
quasi minimum spatii, quod brevis
obtinet syllaba, unum
tempus veteres
vocaverunt: a
brevi enim ad longam
D. Verum est.
M. Sequitur jam, ut illud quoque
animadvertas, quoniam ut in numeris ab
uno ad duo est prima progressio; ita in
syllabis, qua scilicet a
brevi ad longam
longam duplum temporis
habere debere: ac per hoc si spatium
brevis occupat, recte unum
vocatur; spatium item quod
longa occupat, recte duo tempora
The morula
The tenor and the pausa
The tenor
The distinction
Commemoratio brevis
Scolica enchiriadis
Musica enchiriadis
Alcuin, Remigius & Guido
Metric chant
Unmetered poetry
Tempus antiquorum
Poetic metre
poetic metre
The symbolism of chant rhythm
Academic treatment
De Grocheo