Hemiola [hemiolia] (from Gk. hemilios: ‘the whole and a half’; Lat. sesquialtera; It.: emiolia)
- Julian Rushton
[hemiolia] (from Gk. hemilios: ‘the whole and a half’; Lat. sesquialtera; It.: emiolia)
The ratio 3:2. The term was first applied to music in connection with the theory of pitch: when the string of the monochord was divided in this ratio the two lengths sounded the interval of a 5th. From the 15th century, it was used to signify the substitution of three imperfect notes for two perfect ones in tempus perfectum (mensuration with three semibreves to the breve) or prolatio maior (three minims to the semibreve). Such substitutions, which were usually notated using coloration, were widely used in 15th-century music. They were particularly prevalent in the English carol repertory, which was described by Bukofzer as ‘hemiola music pure and simple’ (ex.1).
By extension, ‘hemiola’ in the modern metrical system denotes the articulation of two units of triple metre as if they were notated as three units of duple metre: in ex.2, from Act 4 of Lully’s Le bourgeois gentilhomme (...