Music Theory: Working with Compound Time Signatures
Just a wee bit trickier than simple time signatures are compound time signatures. Music theory gives you a short list of rules that help you immediately tell when you’re dealing with a compound time signature:
The top number is evenly divisible by 3, with the exception of time signatures where the top number is 3. Any time signature with a top number of 6, 9, 12, 15, and so on according to the multiples of 3 is a compound time signature. However, 3/4 and 3/8 aren’t compound time signatures because the top number is 3 (they’re simple time signatures). The most common compound time signatures are 6/8, 9/8, and 12/8.
Each beat is divided into three components. Three eighth notes are beamed together, as are six sixteenth notes. You can see the “three‐based” grouping of beamed notes used in compound time.
Using measures to count in compound time
One big difference between music in a simple time signature and music in a compound time signature is that they feel different, both to listen to and to play.
In compound time, an accent is not only placed on the first beat of each measure (as in simple time), but a slightly softer accent is also placed on each successive beat. Therefore, there are two distinctly accented beats in each measure of music with a 6/8 time, three accents in a piece of 9/8 music, and four accents in a piece of music with a 12/8 time signature.
Here are a few examples of compound time signatures:
6/8: Used in mariachi music
12/8: Found in 12‐bar blues and doo‐wop music
9/4: Used in jazz and progressive rock
To determine the number of accents per measure under a compound time signature, divide the top number by three. Doing so helps you find the pulse in the music you’re playing and, therefore, where to put the accents. In a piece of 6/8 music, for example, you would put the accent at the beginning of each measure, but you also would put a slight accent at the beginning of the second group of eighth notes in a measure.
Counting 6/8 time
In a compound 6/8 time signature, you accent the first and the second sets of three eighth notes. For example, the beat accents you see below would go like this:
ONE two three FOUR five six ONE two three FOUR five six
Counting 9/4 time
If the time signature is something unusual, like 9/4, you would count off the beat like so:
ONE two three FOUR five six SEVEN eight nine
Practicing counting beats in compound time
Practice counting out the beats in the following exercises. When counting these beats out loud, remember to give the first beat a slight stress and put an additional stress at the pulse points of the measure, which are generally located after every third beat.
The ands in the beat patterns are meant to capture the lilt of some of the notes within the beat. This method isn’t exactly scientific, but it should give you a general idea of how to count out beats in different time signatures.
ONE two three FOUR‐and five six | ONE two three FOUR five six | ONE two three FOUR five six
ONE two three FOUR‐and‐five‐and‐six‐and | ONE two three FOUR five six | ONE two three FOUR‐and‐five‐and‐six‐and
ONE two three FOUR five six SEVEN eight nine | ONE two three FOUR‐and‐five‐and‐six‐and SEVEN eight nine