Metrics

What it means

Metrics is the study of the regular measure of time in music and verse: of beats, bars, and their relations of accent. It describes the even grid against which the actual rhythmic event stands out. To be distinguished from it is rhythm, which concerns the concrete course of durations — the metre is the measure, the rhythm what happens within it.

In the notation

The metre is fixed by the time signature and made visible by barlines. The upper number gives the number of beats, the lower their value. From the type of metre an order of strong and weak beats results: in four-four time the first is heaviest, the third moderately accented, the second and fourth light. Twofold beats are to be distinguished from threefold ones — in six-eight time every beat divides into three eighths, not two.

Musical use

Beyond the individual bar the principle continues to act on a larger scale: bars, too, relate to one another as strong and weak, and phrases form regular groups — the eight-bar period is the best-known example. This overarching order explains why an irregular group of bars stands out.

The musical appeal often arises from contradiction to the metre: syncopation shifts the accent against the counting order, the hemiola combines two bars in triple time into three larger units, the duplet sets a twofold division against a threefold beat. Without an audible metre there would be nothing for this to work against.

Bear in mind that older music does not know this grid: monophonic chant and mensural polyphony are organized according to text and voice leading, not according to barlines.

Performance practice

Keep the metre internally in mind, even when the music runs against it — syncopations work only if the grid remains present. Do not accent the strong beats mechanically; the order should be perceptible, not paraded. And phrase across the barline where the melody demands it.