Triple metre
A three-part time signature.
What it means
Triple metre is the collective term for all time signatures with a three-part division — that is, those with three beats per bar, for instance 3/4, 3/8, or 3/2. Its counterpart is formed by the even-numbered time signatures with two or four beats.
The term comes from mensural theory, where the triple division was carried under the name tempus perfectum: three counted as the perfect number, and the signs of mensural notation distinguished between triple and duple division. This origin explains why the word has survived to this day.
Triple metre is to be distinguished from compound time signatures such as 6/8. There are two beats, each subdivided into three; the triple division thus lies on a different level. A nine-eight time unites both: three beats, each divided into three.
In the notation
Triple metre is recognizable by the numeral 3 in the numerator of the time signature. The beaming groups the smaller values into units of one beat each and thereby shows the three-part division. A full bar is filled by a dotted note value, in three-four time for instance by a dotted half.
Musical use
Triple-metre bars carry a large part of dance music: minuet, waltz, Ländler, polonaise, mazurka, sarabande, and courante. Beyond dance, too, they shape whole movement types, for instance the scherzo. The effect rests on the pull between one heavy and two light beats, which is worked out differently depending on the genre — sometimes with a strongly accented one, sometimes with the weight on the two, as individual dances demand.
Performance practice
Keep the second and third beats lighter than the first; too heavy a third quarter is the most common error and makes the bar heavy-footed. At a fast tempo, feel the whole bar as a single beat. Watch the peculiarities of the respective dance, for not every triple-metre bar accents the one most strongly. And with eighth-note movement, check the beaming, to distinguish between triple metre and compound metre.