Swing

In the previous section, we pretended that every beat divides evenly into either two or three divisions. That’s not true. Even within the musical cultures we’re talking about in this text, there’s a third category: swing. In “swung” music, associated particularly with jazz, the beat divides into two unequal parts, with the first part longer and the second part shorter. Nevertheless, when written down, swung music is typically written as if it is in simple meter, and performers simply know to take what look like two even divisions of the beat and make them unequal.

Often, the first division of the beat is roughly twice as long as the second. When that’s the case, swing may not be easy (or useful) to distinguish from compound meter. The use of terms may come down in part to context: jazz musicians and commercial musicians are likely to use the term “swing” for music that often uses long-short patterns within the beat even if occasionally there are three even notes per beat.

It’s also common, however, for the length ratio between the first and second divisions of the beat to be somewhere between 1:1 and 2:1. When this is the case, we typically describe the music using the terminology of simple meter, including time signatures like 2/4, 3/4, and 4/4, but with the knowledge that the beat divisions are unequal in length.