12.3 12-bar blues

As already mentioned, blues composer W.C. Handy claimed to have noticed a repetitive chord sequence in the plantation song that inspired him. The chord pattern that Handy noted down is a succession of primary chords in a specific order. It is now known as 12-bar blues and it is a structure understood by all jazz and popular musicians. It is not the only structure used in blues songs and there are many variants of it, but all of them contain the same basic ingredients.

When we listen to music often what strikes us first is the rhythm. If you tap your foot or nod your head, you are feeling a beat. In any music, beats are grouped, usually into twos, threes or fours and each group of two, three or four beats is called a bar. The 12-bar blues is defined by the order of the three primary chords and the way they are grouped by rhythm. Blues music is in common or 4/4 time, that is, each bar has four beats, usually at a moderate speed. The blues pattern takes up 12 bars of music (12 x 4 beats), and fits neatly with the common three-line verse structure of the lyrics as the 12 bars can be divided into three 4 bar sections. At its simplest, each verse finishes with the end of the 12-bar sequence, and the sequence is repeated for each verse of the lyrics.

Watch this video, which explains how the 12-bar blues structure works.

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Transcript: Video 3

NAOMI BARKER

In this film, I'm going to show you how the 12 bar blues structure works. A 12 bar blues is created by using the 3 primary chords, chord I, chord IV, and chord V, in a specific order. We can call this a chord sequence. In the 12 bar blues sequence, the way these chords are repeated and grouped is defined by metre, that is, the number of beats in each bar. Blues music is usually in common time, which means that there are 4 beats to a bar. For a 12 bar blues, we need 12 bars of music. So that is 12 times 4 beats. The 12 bar blues sequence can be used in any key, but to make it easy, I'm going to show you how a 12 bar blues works in the key of C. Remember, this means that do is C. So on the keyboard, chord I is a C chord, like this.

[MUSIC PLAYING]

Chord IV is an F chord, like this.

[MUSIC PLAYING]

And chord V is a G chord, like this.

[MUSIC PLAYING]

Let me play those again.

[MUSIC PLAYING]

This graphic shows how the three primary chords are split up over the 12 bars that form the 12 bar blues sequence. As you can see, the 12 bar blues starts with 4 bars of chord I. As I'm playing with in C major, that means 4 bars of a C chord. Then we have 2 bars of chord IV, that is an F chord, before going back to the C chord, and so on. I'm going to start counting 4 and placing the chords in the pattern of the blues while I continue to count out the beats.

[MUSIC PLAYING]

1 2, 3, 4. 2, 2, 3, 4. 3, 2, 3, 4. 4, 2, 3, 4. 5, 2, 3, 4. 6, 2, 3, 4. 7, 2, 3, 4. 8, 2, 3, 4. 9, 2, 3, 4. 10, 2, 3, 4. 11, 2, 3, 4. 12, 2, 3, 4. Now, this doesn't sound very exciting because all I'm doing is playing simple chords and not creating any rhythms or melody around them. If I start adding rhythms and silences, you can see how the pattern can quickly become more interesting.

[MUSIC PLAYING]

To show you how this works in practise, let's take a section of Rock Around the Clock by Bill Haley and the Comets. This is not a blues song, but many, many rock and roll songs, popular songs, and jazz pieces, use this structure. The verses of this song follow the 12 bar blues pattern. First, listen to this extract while I start you off counting the beats during the introduction. The tempo is fast, so it's easy to lose track. I'll stop counting where the blues pattern starts. I want you to keep your counting going so that you get the feel of how the words fit with the rhythm.

[MUSIC - BILL HALEY AND THE COMETS, "ROCK AROUND THE CLOCK"]

1, 2, 3 4. 1, 2, 3, 4. 1, 2, 3, 4. 1, 2, 3 4. 1, 2, 3, 4. 1, 2, 3, 4. 1, 2, 3, 4. 1, 2, 3, 4.

VOICE

Put your glad rags on, join me hon. We'll have some fun when the clock strikes 1:00. We're going to rock around the clock tonight, we're going to rock, rock, rock till broad daylight. We're going to rock, going to rock around the clock tonight.

NAOMI BARKER

Now you have an idea of the tempo. Let's focus on the chord structure in the verse. The words, glad rags, mark the first bar of the pattern and the start of the 4 bars of chord I. The 2 bars of chord IV start at the words, going to rock, and then it moves back to chord I at, rock, rock, rock. In the last line, the words, rock, going to rock, take chord V, and the verse ends with a return to chord I on the syllable, night, of tonight. I've colour coded the lyrics here so that you can focus your listening in the right places. Listen now, paying close attention to the chord changes. You may find it helpful to hone in on the bass part as this moves more slowly from one bar to the next. I don't expect you to be an expert in following a 12 bar blues structure after only one or two hearings. You may like to pause and replay this a few times to make sure you're really comfortable with the principles of how the pattern works.

[MUSIC - BILL HALEY AND THE COMETS, "ROCK AROUND THE CLOCK TONIGHT"]

End transcript: Video 3

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Video 3

In the video you saw a graphic representation of the 12-bar blues sequence. Look at it again now, to remind yourself of the pattern. If you have access to a musical instrument, you could try it out yourself.

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This shows the 12-bar blues structure in C.

As you will have seen from the video, this chord pattern became an important element in the foundation of jazz and of later styles of popular music including rhythm and blues and rock and roll. Many pieces of music that today we might recognise as typical rock and roll songs or ‘jazz standards’ use structures that are derived from the blues. If you would like to build a playlist of music that uses 12-bar blues, start with Bill Haley’s ‘Rock around the clock’, Duke Ellington’s ‘C-jam blues’, Louis Armstrong’s ‘West end blues’, Johnny Cash’s ‘Folsom prison blues’ and Robert Johnson’s ‘Sweet home Chicago’. These are just some examples that will give you an idea of how versatile the 12-bar blues structure is. Keep the graphic handy so you can follow the pattern of chords as you listen to these songs. This will help you become more familiar with how it sounds and help you to recognise it in other songs you listen to.