Transcript
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"]