Simple and Compound Time Signatures

Organizing music into measures, each containing a fixed number of beats, is called meter. In musical notation, meter is indicated by a time signature (also called a meter signature).

A time signature consists of two numbers, one above the other. The upper number tells us how many beats are in each measure, while the lower number indicates which type of note receives one beat (e.g., a quarter note, eighth note, and so on). Time signatures can be broadly categorized into two types: simple and compound.

Simple Time Signatures

In simple time signatures, the lower number specifies the note value that represents one beat, while the upper number indicates how many beats are in each measure. In simple time, each beat can be divided into two equal parts.

For example, in 4/4 meter, there are four beats per measure, and each beat is represented by a quarter note. Each quarter note can be divided into two eighth notes: 

Meters are classified by the number of beats in a measure. The simplest meter is called simple duple meter. It consists of two beats per measure: one strong (accented) beat and one weak (unaccented) beat. Common examples include 2/2, 2/4, and 2/8 meters:

Next there is the simple triple meter, which consists of measures with three beats. The first beat is the downbeat (accented), while the second and third beats are unaccented. Common examples of simple triple meter include 3/2, 3/4, and 3/8 meters:

Another common metrical pattern is the simple quadruple meter, which consists of four beats per measure. In simple quadruple meter, the first beat (downbeat) is the strongest, while the third beat has a secondary accent. The second and fourth beats are weaker. Common examples of simple quadruple meter include 4/2, 4/4, and 4/8 meters:

Summary of Simple Time Signatures

Simple time signatures are easy to identify because each beat is divided into two equal pats. The upper number of time signature tells us how many beats are in a measure, while the lower number indicates the note value for each beat.

There are three main types of simple meters based on the number of beats per measure: duple (two beats), triple (three beats), and quadruple (four beats). Each meter has characteristic time signatures, which define the structure of the music. This regular division provides a steady and predictable rhythm, commonly used in marches, dances, and folk music.

Compound Time Signatures

Unlike simple time signatures, where each beat is divided into two equal parts, compound time signature feature beats that are divided into three equal parts. In compound time, the upper number of time signature tells us the number of subdivisions (not the actual beats) in each measure.

For example, in 6/8 meter, the upper number (6) indicates that there are six eighth notes in the measure. The eighth notes are grouped into two beats, each consisting of three eighth notes. Each of these beats is represented by a dotted quarter note.

To find the actual number of beats, divide the upper number by three. The lower number represents the note value for the division of each beat, which is an eighth note in this case.

Types of Compound Meters

Meters in compound time are classified by how the subdivisions are grouped. The most basic is the compound duple meter, which consists of two beats per measure, each subdivided into three equal parts. Common examples include 6/2, 6/4, and 6/8 meters:

Other examples of compound meters include compound triple meter, which consists of three beats per measure, each subdivided into three equal parts. An example is 9/8 meter, where the upper number (9) indicates nine eighth-note subdivisions, grouped into three beats (each a dotted quarter note).

Finally, there is compound quadruple meter, which consists of four beats per measure, each subdivided into three equal parts. An example is 12/8 meter, where the upper number (12) indicates twelve eighth-note subdivision, grouped into four beats (each a dotted quarter note).

Key Differences Between Simple and Compound Time

The main distinction between simple and compound time is in how beats are subdivided. In simple time, beats are divided into two equal parts. In compound time, beats are subdivided into three equal parts, giving the music a more lilting, triple-based feel, often found in waltzes, jigs, and other styles that emphasize a flowing rhythm.