Welcome back to our series of articles about the time signature. In the last article, we talked about the regular time signature. Now, it's time to talk about the irregular time signature. Ready? Let's do it.

Reviewing important concepts

I want us to review a few key concepts to make sure we have a solid foundation for understanding what the irregular time signature is.

♣︎ Rhythm

A rhythm is a group of sounds of different durations.

♣︎ The numbers on the Time signature

First, the number at the bottom of the time signature indicates the unit and the superior number, how many units will be in each measure. For example, 2/4 means that the unit is the quarter note and that there will be 2 quarter notes per measure (or a sequence of notes with a corresponding value of 2 quarters, e.g. a half note, two eighth notes, four sixteenth notes, etc.).

You can review this in our dedicated article.

♣︎ Regular simple time signature

In a nutshell, the regular time signatures have a superior number divisible by 2, 3, or 4.

♣︎ Regular compound time signature  

Anytime you see a time signature with an "8" as the bottom number, you have a compound time signature. The beat is divided into three sub beats.

♣︎ Simple vs compound time signatures

As you can see below, the main differences between the simple and the compound time signatures are the bottom number and the subdivision of the beat. In other words, the simple time signature is x/4, and the compound time signature is x/8.
What is more, in a simple time signature, the beats will be divided between a binary way and the compound in a ternary way.

Also, the unit of tempo for simple time signatures is a quarter, and the unit of tempo for compound time signatures is a dotted quarter.

Now, what these two types of time signatures have in common is that there is symmetry within each measure. You can see it in the image below, in which you can see that the subdivision possible in both types of time signatures always generates symmetry within the bar.

Now, the irregular time signature has no symmetry 🤯. Having said that, let's dig deeper into this type of time signature.

The irregular time signature

✋🏾 Before giving you the definition of the irregular time signature, let's look at an example: 7/8.

If you try to group the notes creating a certain symmetry, it will not be possible. If you try to do it the way you divide a simple regular bar, you will have an eighth note left over.

Now, if try to group the notes the way you divide a simple compound time signature, you will have one eight note left over.

As you can see, the irregular time signature has no symmetry. And this happens because this type of time signature results from a combination of a regular simple time signature and a compound time signature 💁🏼.

We divide the measure in a way that we can find certain order. The subdivision depends on the rhythm we want to create. We will talk about this in detail in an upcoming article.

If you listen to a song with an irregular time signature and try to clap in x/4, you will get lost 🤪. This type of time signature generates songs in which it is difficult for us to follow the rhythm by clapping our hands or moving our heads. Also, the irregular time signature evokes a feeling of suspension or that the bars are somehow incomplete. And it is not that they are incomplete. The truth is that we don't find this type of time signature in the most popularized and commercial music. Consequently, we do not feel very familiar with it.

I leave a couple of songs with this type of time signature for you to listen to.

Time signature: 7/8

Time signature: 13/8
Time signature: 5/8

Pro tip: how to count in these types of time signature

To count in this type of time signature, you can do it in two ways. First, you can count by eighth notes.

That counting works very well for measures like 5/8. But, for larger time signatures, this can be tricky, so it's best to count in quarter notes and dotted quarter notes.

To finish, remember the time signature can change in a song or have time signatures that seem very complex. For example, Tool's Schism, for the most part, has a time signature that goes from 5/8 to 7/8.

🎧 Please, don't be overwhelmed or intimidated by the apparent complexity of the time signature of certain songs. The key is to go from the general to the specific. Also, to listen to lots and lots of music of all kinds, this way, you'll become familiar with the different time signatures.

Listening to music frequently and consciously will develop your musical intuition. Along with a theoretical foundation, you will master this subject 🙌🏼.

Thanks for reading!

See you next time 🖖🏿