How Many Measures are in a Blues Song?

There are 12 measures in a blues song. Each section of the song is 4 measures long. The song form is AAB.

The 12-bar blues

The 12-bar blues is a musical form that is commonly found in blues and rock music. It is not limited to those genres, however. The 12-bar blues is characterized by its length (12 measures), chord progression (typically I-IV-V), and lyrics (often about love, poverty, or other problems).

The chord progression

Most blues songs are 12 bars long. The 12-bar blues is a chord progression that uses the I, IV, and V chords of a key. It’s usually played in 12/8 time, which feels more like counting “1 and 2 and 3 and 4 and” instead of “1-2-3-4.”

The chord progression can be divided into three four-bar sections, each with a different feel. The first section is known as the “Turnaround.” It usually consists of the I and IV chords, or sometimes the I, IV, and V chords. The second section is called the “Hook,” because it’s where the catchy melody or lick is usually found. This section usually has the IV and V chords. The last section is just a repeat of the first section, but with different words.

So in a 12-bar blues in the key of C, the chord progression would be:
C – C – C – C
F – F – C – C
G – F – C – C

The turnaround

The turnaround is one of the most important parts of the blues and one of the most fun to play. It’s that part of the song where the singer or band “turns around” and heads back to the top of the form. The turnaround usually happens at the end of the last chorus or bridge and signals the end of the song.

There are a lot of different ways to approach turnarounds, but one of the most common is to use a 12-bar blues progression. This progression is built on the I, IV, and V chords, which are also known as “the blues chords.” The 12-bar blues progression is made up of these chord changes:

I I I I
IV IV I I
V IV I V

You can see that there’s a lot of repetition in this progression. That’s because the aim of the turnaround is to create a sense of closure, so it’s important to keep things simple. One way to do this is to use only three chords, which is why the I, IV, and V chords are so important in turnarounds.

Another way to create a sense of closure is to end on the root chord, which in this case would be the I chord. This gives the listener a sense of resolution and helps to create a strong ending.

8-bar blues

A blues song is typically made up of 12 measures, or 3 chord progressions of 4 bars each. However, some blues songs only have 8 measures, or 2 chord progressions of 4 bars each. These are called 8-bar blues. Let’s take a look at some examples of 8-bar blues songs.

The chord progression

The chord progression of an 8-bar blues is typically either the I-IV-V progression, or a variation of it such as I-VII-V. The I, IV and V chords are each played for two bars, while the VII chord is usually played for just one bar. This gives the basic structure of an 8-bar blues as:

I-I-I-I
IV-IV-I-I
V-V-I-I
or

I-I-I-(VII)
IV-(VII)-V ( sometimes written as V7/VII)
V-(VII)-V
I-(VII)-V

The turnaround

The turnaround is the last two measures of a blues song. It usually consists of a I-IV-V chord progression in the key of the song, which leads back to the top of the next verse. The turnaround can be a very important part of a blues song, as it helps to create the sense of “coming full circle” that is so important in the blues.

There are many different ways to play a turnaround, and there is no one right way to do it. Some common turnaround progressions include:

I-IV-V: A classic blues progression that can be used in any key.

I-VII-V: A slightly more sophisticated sounding progression that can be used in any key.

I-VI-II-V: A progression that is commonly used in major keys.

16-bar blues

A blues song is typically made up of 12 bars, or measures. The first 4 measures are the same, then the next 4 measures are different, and the last 4 measures are the same as the first 4. This pattern is repeated for the rest of the song.

The chord progression

In a typical 16-bar blues, the first eight bars are devoted to the Setup, which is where the singer establishes the situation, establishes the characters, and gives a little bit of background information. This is followed by the Story, which is where the singer tells the actual story of what happened. The final eight bars are known as the Resolution, where the singer wraps up loose ends and gives the listener a sense of closure.

The turnaround

The turnaround is a two-measure phrase that signals the end of a chorus and the beginning of the next verse. The most common turnaround is built on the chord progression I-VII-VI-V, which in the key of C would be C7-F7-E7-D7. This progression can be played as shown below, with each chord getting one measure.