# A Dictionary of Music and Musicians/Time-Signature

​TIME-SIGNATURE (Lat. Signum Modi, vel Temporis, vel Prolationis; Germ. Taktzeichen). A Sign placed after the Clef and the Sharps or Flats which determine the Signature of the Key, in order to give notice of the Rhythm in which a Composition is written.
Our present Time-signatures are directly descended from forms invented in the Middle Ages. Mediæval Composers used the Circle—the most perfect of figures—to denote Perfect (or, as we should now say, Triple) Rhythm; and the Semicircle for Imperfect or Duple forms. The Signatures used to distinguish the Greater and Lesser Modes, Perfect or Imperfect—Signa Modi, Modal Signs—were usually preceded by a group of Rests, showing the number of Longs to which a Large was equal in the Greater Mode, and the number of Breves which equalled the Long in the Lesser one—that is to say, three for the Perfect forms, and two for the Imperfect. Sometimes these Rests were figured once only: sometimes they were twice repeated. The following forms were most commonly used:—
Greater Mode Perfect.
Greater Mode Imperfect.
Lesser Mode Imperfect.
Combinations of the Greater and Lesser Modes, when both were Perfect, were indicated by a Point of Perfection, placed in the centre of the Circle, as at (a) in the following example. When the Greater Mode was Perfect, and the Lesser Imperfect, the Point was omitted, as at (b). ​When both Modes were Imperfect, or the Greater Imperfect and the Lesser Perfect, the difference was indicated by the groups of Eests, as at (c) and (d).
(a) Both Modes Perfect.
(c) Both Modes Imperfect.
(b) Greater Mode Perfect, and Lesser Imperfect.
(d) Greater Modes Imperfect, and Lesser Perfect.
The Circle and the Semicircle, were also used either alone or in combination with the figures 3 or 2, as Signatures of Time, in the limited sense in which that term was used in the Middle Ages; i.e. as applied to the proportions existing between the Breve and the Semibreve only—three to one in Perfect, and two to one in Imperfect forms.
Perfect Time.
The same signs were used to indicate the proportion between the Semibreve and the Minim, in the Greater and Lesser Prolation; but generally with a bar drawn perpendicularly through the Circle or Semicircle, to indicate that the beats were to be represented by Minims; and sometimes, in the case of the Greater Prolation, with the addition of a Point of Perfection.
The Greater Prolation.
Combinations of Mode, Time, and Prolation sometimes give rise to very complicated forms, which varied so much at different epochs, that even Ornitoparchus, writing in 1517, complains of the difficulty of understanding them. Some writers used two Circles or Semicircles, one within the other, with or without a Point of Perfection in the centre of the smaller one. The inversion of the Semicircle ((symbol characters)) always denoted a diminution in the value of the beats, to the extent of one-half; but it was only at a comparatively late period that the doubled figure ((symbol characters)) indicated an analogous change in the opposite direction. Again, the barred Circle or Semicircle always indicated Minim beats; but the unbarred forms, while indicating Semibreves, in Mode, and Time, were used, by the Madrigal writers, to indicate Crotchet beats, in Prolation.
The application of these principles to modern Time-signatures is exceedingly simple, and may be explained in a very few words. At present we use the unbarred Semicircle to indicate four Crotchet beats in a bar; the barred Semicircle to indicate four Minim beats, in the Time called Alla breve, and two Minim beats in Alla Cappella. Some German writers once used the doubled Semicircle, barred, ((symbol characters)) for Alla breve which they called the Grosse Allabrevetakt, and the ordinary single form, barred, for Alla Cappella—Kleine Allabrevetakt: but this distinction has long since fallen into disuse.
The Circle is no longer used; all other forms of Rhythm than those already mentioned being distinguished by fractions, the denominators of which refer to the aliquot parts of a Semibreve, and the numerators, to the number of them contained in a bar, as 2/4 ( = 2/), 3/2 ( = 3/) etc. And even in this we only follow the mediaeval custom, which used the fraction 3/2 to denote Triple Time, with three Minims in a bar, exactly as we denote it at the present day.
[ W. S. R. ]
* ↑ See Mode.
* ↑ The reader must be careful to observe tbe position of these Rests; because it is only when they precede the Circle or Semicircle, that they are used as signs. When they follow it, they must be counted as marks of silence.
* ↑ See p. 17b.
* ↑ See Prolation.
* ↑ See vol. iii. p. 12.