the duration of all other notes is and always has been regulated. [See Time-Signature.]
Of these combinations, there are two distinct orders, classed under the heads of Common (or Duple) Time, in which the contents of the Bar[1]—as represented by the number of its Beats—are divisible by 2; and Triple Time, in which the number of beats can only be divided by 3. These two orders of Time—answering to the Imperfect and Perfect forms of the earlier system—are again subdivided into two lesser classes, called Simple and Compound. We shall treat of the Simple Times first, begging the reader to remember, that in every case the rhythmic value of the Bar is determined, not by the number of notes it contains, but by the number of its Beats. For it is evident that a Bar of what is generally called Common Time may just as well be made to contain two Minims, eight Quavers, or sixteen Semiquavers, as four Crotchets, though it can never be made to contain more or less than four Beats. It is only by the number of its Beats, therefore, that it can be accurately measured.
I. Simple Common Times (Ital. Tempi pari; Fr. Mesures à quatre ou à deux temps; Germ. Einfache gerade Takt). The forms of these now most commonly used, are—
1. The Time called 'Alla Breve,' which contains, in every Bar, four Beats, each represented by a Minim, or its value in other notes.
This species of Time, most frequently used in Ecclesiastical Music, has for its Signature a Semicircle, with a Bar drawn perpendicularly through it[2] (); and derives its name from the fact that four Minims make a Breve.
2. Four Crotchet Time (Ital. Tempo ordinario;[3] Fr. Mesure à quatre temps; Germ. Viervierteltakt) popularly called Common Time, par excellence.
This kind of Time also contains four Beats in a Bar, each Beat being represented by a Crotchet—or its value, in other notes. Its Signature is an unbarred Semicircle (), or, less less commonly, 44.
3. The Time called Alla Cappella—sometimes very incorrectly misnamed Alla Breve—containing two Minim Beats in the Bar, and having for its Signature a barred Semicircle exactly similar to that used for the true Alla Breve already described (No. 1).
This Time—essentially modern—is constantly used for quick Movements, in which it is more convenient to beat twice in a Bar than four times. Antient Church Music is frequently translated into this time by modern editors, each bar of the older Notation being cut into two; but it is evidently impossible to call it 'Alla Breve,' since each bar contains the value not of a Breve but of a Semibreve only.
4. Two Crotchet or Two-four Time, sometimes, though very improperly, called 'French Common Time' (Ital. Tempo di dupla; Fr. Mesure à deux temps; Germ. Zweivierteltakt), in which each Bar contains two Beats, each represented by a Crotchet.
In very slow Movements, written in this Time, it is not at all unusual for the Conductor to indicate four Beats in the Bar instead of two; in which case the effect is precisely the same as that which would be produced by Four Crotchet Time, taken at the same rate of movement for each Beat. It would be an excellent plan to distinguish this slow form of 24 by the Time-Signature, 48; since this sign would indicate the subsidiary Accent to be presently described.
5. Eight Quaver Time (Germ. Achtachteltakt)—that is, eight Beats in a Bar, each represented by a Quaver—is not very frequently used: but an example, marked 88, will be found in the PF. arrangement of the Slow Movement of Spohr's Overture to 'Faust.'
In the Orchestral Score, each Bar of this Movement is divided into two, with the barred Semicircle of Alla Cappella for its Time-Signature. It is evident that the gross contents of a Bar of this Time are equal, in value, to those of a Bar of 44; but there is a great difference in the rendering, which will be explained later on.
6. Two Quaver Time (Germ. Zweiachteltakt, or Viersechszehntheiltakt), denoted by 28 or 416 is also very uncommon: but examples will be found in the Chorus of Witches in Spohr's Faust, and in his Symphony 'Die Weihe der Töne.'
The forms of Simple Common Time we have here described suffice for the expression of every kind of Rhythm characterised by the presence of
- ↑ Strictly speaking, the term 'Bar' applies only to the lines drawn perpendicularly across the Stave, for the purpose of dividing a Composition into equal portions, properly called 'Measures.' But, in common language, the term 'Bar' is almost invariably substituted for 'Measure,' and consequently used to denote not only the perpendicular lines, but also the Music contained between them. It is in this latter sense that the word is used throughout the present article.
- ↑ Not a 'capital C, for Common Time,' as neophytes sometimes suppose.
- ↑ Not to be mistaken for the 'Tempo ordinario' so often used by Handel, in which the term 'Tempo' refers to pace, and not to rhythm, or measure.