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Your FIRST 12 Bar Blues on Harmonica | Beginner Blues Harmonica Lesson

As a blues harmonica player, you simply NEED to understand the 12 bar blues. In this lesson, we'll delve into what the 12 bar blues is, examine its structure, and explore how to play blues harmonica solos over the 12 bar structure. You will need a harmonica in the key of C.

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What is the 12 bar blues?

The 12 bar blues is a chord progression that spans 12 measures, or 'bars'. It is by far the most widely used form of blues structures - almost all the classic blues songs you know will use this structure.

The 12 bar blues is a simple structure to learn, making it an excellent starting point for harmonica players who want to explore blues music.

Structure of the 12 bar blues

The 12 bar blues follows a specific sequence of chords that repeats over and over.

Here's a diagram showing the 12 bar blues structure:

12 bar blues basic chord structure with I, IV and V chords

What does a 12 bar blues sound like?

You're probably familar with a classic 12 bar blues sound, so let's have a listen in this demo video:

Chords used in the 12 bar blues

The chords in a 12 bar blues progression are denoted by Roman numerals. The three primary chords used are the I, IV, and V chords (in fancy musical terms that's the tonic, subdominant, and dominant chords, respectively).

I Chord: This is the home chord, providing a stable and resolved sound. In the key of G, the I chord is G.

IV Chord: The subdominant chord adds tension and movement. In the key of G, the IV chord is C.

V Chord: The dominant chord creates anticipation and leads back to the tonic. In the key of G, the V chord is D.

The basic structure can be represented as follows:

  1. Bars 1-4 (I Chord): The progression begins with the I chord. For example, in the key of G, the I chord would be G.

  2. Bars 5-6 (IV Chord): Transition to the IV chord for the fifth and sixth bars. In the key of G, this would be a C chord.

  3. Bars 7-8 (I Chord): Return to the I chord for the seventh and eighth bars.

  4. Bars 9-10 (V Chord): Move to the V chord in the ninth bar. In the key of G, this would be a D chord. Bar 10 is the IV chord again.

  5. Bars 11-12 (I Chord): Conclude the progression by returning to the I chord for the eleventh and twelfth bars.

To recap, let's have another look at that structure:

12 bar blues basic chord structure with I, IV and V chords

Below we'll move on to playing harmonica over the 12 bar blues!

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How to play harmonica over a 12 bar blues

Let's play along to a 12 bar blues in the key of G, using a standard C diatonic harmonica.

It's easy to play along to the 12 bar structure, and you don't even need to play clean notes.

For the I chord, you need to play -123 (1, 2 and 3 draw all together). For the IV chord, play 123 (1, 2 and 3 blow all together). For the V chord, play -12 (1 and 2 draw together). Here's a summary of those tabs:

Harmonica tabs for I, IV and V chords.

Watch the video at the top of this page to play along!


The 12 bar blues is a timeless musical structure that you just have to know if you're going to play the harmonica. But it's not just a set of chords, it's a canvas for expressing emotions and telling musical stories. So grab your harmonica and dive into the rich world of the 12 bar blues.

I hope you enjoyed this lesson on playing the 12 bar blues. See you again soon!

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