The 12-bar blues progression is the main underpinning of the vast majority of blues tunes out there. In order to start playing blues (and to take most of the other blues lessons on WholeNote), you will want to know what a 12-bar blues progression is. The most basic explanation of the 12-bar blues need answer only two questions: "What chords/notes do I play?" and "What order/progression do I play them in?"
The basic concept of the 12-bar blues is the I-IV-V progression, where I, IV and V represent the chords or notes that you will be using. To this, you will undoubtedly have two questions, "what the hell is I-IV-V," and "once I know what "I-IV-V" is, how do I use it?"
What the Hell is I-IV-V?
When you play a blues progression, you will only need to use 3 chords (isn't life simple?). The principle of I-IV-V tells you which chords to use, as follows: a slightly oversimplified approach, which happens to work for the keys of A,C,D,E and G, which is enough for right now (see page 4 of the lesson for other keys), is to simply count out the letters of the alphabet starting with the key you're playing in. The first, fourth and fifth letter you count represent the chords that you will be using in your blues progression.
For the key of A we count: A
Thus, for the key of A, we will be using A-D-E as our I-IV-V progression. Likewise if you count out starting with E, you will find that for the key of E we will use E-A-B as our I-IV-V.
Music Theory lovers refer to the I as the "tonic", the IV as the "subdominant", and the V as the "dominant". I won't use these terms in this lesson, but knowing that may help you understand what other people are talking about sometimes.
How do I use the I-IV-V?
The basic concept of the 12-bar blues is to create and resolve tension. Once you get used to the progression, you will see how the V generally creates tension in your progression and the I generally resolves tension. I usually think of the 12-bar progression as being divisible into 3 little pieces of 4 bars each. The first four bars just sort of set things up, using the relaxed I chord. In our second 4-bar segment, a little tension is introduced by the IV chord in bars 5-6, but resolved by the I chord in bars 7-8. In our third four-bar segment, the tension reaches new heights in the 9th bar, where the V chord makes its first appearance. The tension is gradually resolved in bars 10-11 before using a "turnaround" to get you all tense again for the next 12 bars. A "turnaround" is generally a 1-2 bar fill at the end of the 12-bar progression, which sets us up for our next 12-bars. Turnarounds can be very simple or very complicated, and there are several lessons on blues turnarounds here at WholeNote.
The most basic form of the blues progression (as shown below in the key of E) is to play 12 bars as follows:
Note how the V is used to create tension in the 9th bar. Also note the primitive turnaround used here, where the last bar starts in I and then uses V to create tension going into the next 12-bar progression.
Try playing along with the 12-bar progression shown below to get a feel for it. Theoretically, the V should be a Bmajor chord, but I've used a B7 chord instead, since it's easier. As you will see on the following pages, seventh chords are preferable for the blues, anyway.
Pages 2 and 3 of this lesson will show you easy variations that improve on this basic version.