1.235 proportion
ES: proporción,
I: proprozione (?),
F: proportion,
D: ?,
NL: ?,
DK: ?,
S: ?,
FI: suhde.
[Latin: proportio.] Described in great detail by Gaffurius, in
Practica musicae (published in Milan in 1496). In mensural notation,
proportion is:
- A ratio that expresses the relationship between the note values that
follow with those that precede;
- A ratio between the note values of a passage and the ‘normal’
relationship of note values to the metrical pulse. (A special case of the
first definition.)
The most common proportions are:
- 2:1 (or simply 2), expressed by a vertical line through the
mensuration sign (the origin of the ‘cut-time’ time signature), or by
turning the sign backwards
- 3:1 (or simply 3)
- 3:2 (sesquialtera)
To ‘cancel’ any of these, the inverse proportion is applied. Thus:
- 1:2 cancels 2:1
- 1:3 cancels 3:1
- 2:3 cancels 3:2
- and so on.
Gaffurius enumerates five basic types of major:minor proportions and their
inverses:
- Multiplex, if the major number is an exact multiple of the minor (2:1,
3:1, 4:2, 6:3); and its inverse, Submultiplex (1:2, 1:3, 2:4, 3:6)
- Epimoria or Superparticular [orig. Epimoria seu Superparticularis],
if the major number is one more than the minor (3:2, 4:3, 5:4); and its
inverse, Subsuperparticular (2:3, 3:4, 4:5)
- Superpartiens, if the major number is one less than twice the minor
(5:3, 7:4, 9:5, 11:6); and its inverse, subsuperpartiens (3:5, 4:7, 5:9, 6:11)
- Multiplexsuperparticular, if the major number is one more than twice the
minor (5:2, 7:3, 9:4); and its inverse, Submultiplexsuperparticular (2:5, 3:7,
4:9)
- Multiplexsuperpartiens, if the major number is one less than some other
multiple (usually three or four) of the minor (8:3, 11:4, 14:5, 11:3); and its
inverse, Submultiplexsuperpartiens (3:8, 4:11, 5:14, 3:11)
He then continues to subdivide each type in various ways. For the multiplex
proportions, for example, he indicates how many times greater the major number
is than the minor:
- If two times greater, the proportion is dupla. If inverted, it's
called subdupla. Examples: 2:1, 4:2, and 6:3.
- If three, tripla; and its inversion, subtripla. Example:
3:1, 6:2, and 9:3.
- If four, quadrupla; and its inversion, subquadrupla.
Example: 4:1, 8:2, and 12:3
Other proportions were possible, but whether they were frequently used is
another question:
- 33:9, triplasuperbipartientetertias
- 51:15, triplasuperbipartientequintas
See also
mensural notation.