Compound & Asymmetrical Meter

The rhythms we’ve seen so far all divide in half (i.e., a quarter = two 8ths, an 8th = two 16ths, etc.). Meters that feature beats like this are called simple meters. Now let’s see how dots impact the way we count and experience different types of meter.

Adding a dot to a rhythm adds half of its value to itself. For example, a dotted quarter note is equal to three 8th notes instead of just two. Thus, all dotted notes divide into three instead of into two halves. Meters that feature dotted notes as their primary beat are called compound meters.

Let’s compare a simple meter with its compound cousin. A measure of 2/4 has two beats and each beat is a quarter note. We can divide each quarter note in half to get two 8th notes. Because the meter has two beats we call 2/4 a simple duple meter. If we add a dot to each quarter note in 2/4 we retain the main beat count of two but now the subdivision of each beat is divided into three 8th notes. The time signature changes to 6/8 to represent the correct number of 8th notes in the measure, but confusingly, it looks like we should count the meter as six 8th-note beats.

But, we generally don’t—unless the tempo is quite slow. We count the first dotted quarter as one and the second as two. We also beam the three 8th notes together to show that they belong to the same beat. The music in 6/8, and other compound meters, has more of a lilt or swinging quality because the beat divides into three. Lullabies and other dance-related pieces often use compound meters to convey a swinging motion.

Since there are two beats in 6/8 we call it a compound duple meter. 3/4 is a simple triple meter and its compound cousin is 9/8, which we call a compound triple meter. 4/4 is referred to as simple quadruple and 12/8 is compound quadruple.

To count a compound meter like 6/8, we add “a” after the “+” to make “1, +, a, 2, +, a.”

It is crucial to remember that the beat of a compound meter divides in three, not two like a simple duple meter. The two examples demonstrate how to use correct beaming to clearly show the underlying beat structure of the meter.

Now that we understand the difference between simple and compound, we can combine the two concepts into a single, asymmetrical meter. It is so named because the measure cannot be divided evenly in half; one side will always be longer or shorter than the other. For example, 5/8 divides into 2+3 or 3+2. Even though there are two large beats, since one is simple and the other is compound, the measure will always feel “off kilter.”

All asymmetrical meters use some combination of 2s and 3s as the underlying beat structure. For example, 8/8 may seem the same as 4/4 but when used as 8/8, the composer would use groupings like 2+3+3, 3+2+3, or 3+3+2, but not 2+2+2+2.

Ties connect two or more rhythmic values together, usually across beats. Ties lengthen the initial note value and can be combined to create lengthy tie chains. Though similar to dots, in that they lengthen rhythmic values, they have specific use cases.

For example, if we had four quarter notes in a measure of 4/4, and wanted to extend the first beat by an 8th, we could either use a dotted quarter followed by an 8th note, or use a tie from the quarter to the first 8th of the 2nd beat beam group. But, if we wanted to extend the “and” of beat two across the middle of the measure, we should use a tie because it keeps the middle of the measure visible and clearly shows where the third beat begins. A tie would also be necessary if extending a rhythmic value across a barline.

If you’re ever unsure of whether to use a dot or a tie, remember these rules:

• Never obscure the middle of a measure with a dotted rhythm.
• Always preserve the underlying beat structure. Allowed exceptions include simple syncopation figures or dotted values that don’t obscure the middle of the measure.

Any non-standard grouping of rhythmic values can be “forced” into a beat. For example, two 8th notes normally fill one beat of 4/4, but if we want three 8th notes in that same amount of time we would write them as a triplet. These are spread evenly across the same amount of time as the two 8th notes.

If we want four notes in that same amount of time, we would, of course, use the standard four 16ths. But if we wanted five, six, or seven notes in that same amount of time, we’d write them as a 16th-note quintuplet, sextuplet, or septuplet, respectively.

We can also force two notes to be evenly spaced in the time of three, as in one of the beats in 6/8 time. This is called a duplet.

Tuplets of any type are always indicated with the corresponding tuplet number above the beam group that makes up the tuplet. If there isn’t a beam group (e.g., three quarter notes) or if the beam group is only part of a larger beat (e.g., a three 16th tuplet on the second half of a two 8th note beat) a bracket is required for clarity.

The best way to learn how rhythmic notation correctly fits within the wide variety of meters is to compose with rhythms. Complete the composition task by following these guidelines:

• Compose an eight-measure piece for two performers.
• Use only rhythms and rests, no pitches.
• The piece must be performable by two humans. You can instruct them to clap, speak, tap, or use other percussive methods.
• Choose your own time signature and switch time signatures as desired (this is called mixed meter), but do not use different time signatures at the same time (this is called polymeter and is an advanced technique).
• Use dynamics, articulation, or lyrics to enliven the composition.