Irregular time signatures
Definition
In simple time music is easily grouped into two quavers whilst in compound time the groupings are of three quavers.
So in 4/4, the music naturally groups into 4 crotchet beats, whilst in 6/8, the grouping would tend to fall into a pattern of 2 groups of 3 quavers (or 2 dotted crotchets).
Irregular time signatures occur when the music does not naturally fall into equal groupings.
5/4 where there are 5 crotchet beats in each bar is perhaps the most common of irregular time signatures. It is not possible to divide the grouping of notes equally within the bar. This results in an irregular grouping pattern of 3 and 2, or 2 and 3.
Listen particularly to the opening of 'Take 5' which is in 5/4 time. The music is grouped like the first example above – 123 + 12. This is especially clear in the first 20 seconds or so before the saxophone soloist enters.
In 'Money' the music is in 7/4. The grouping of the beats in this example is 1234 + 123.
Examples
An example of irregular time signatures in 'Take 5' by Dave Brubeck.
An example of music in 7/4.
Related concepts
- 2, 3 or 4 beats in the bar (N3 & N3 Tech)
- Simple time (N4 & N4 Tech)
- Compound time (N4 & N4 Tech)