12 Bar Blues

What is the 12 Bar Blues?

Play the 12 Bar Blues in any key

•  Aural training using the 12 bar blues

Blues chords typically include.a 7th note

Notes of Chords E7 A7 and D7.

•. 12 Bar Blues in the key of E A & D major.

Each key signature has it’s own challenges

The one four five chords

The 12 Bar Blues pattern

• 12 Bar Blues in the Key of C

CAGED Guitar System

What is the 12 Bar Blues?

The 12 bar blues is a chord progression that recycles after 12 bars. It’s a universal language that allows musicians to understand and collaborate almost anywhere in the world. Useful as it allows the musicians to test one another’s skills such as improvising, rhythm and general musicality. 

The 12 Bar Blues is a chord progression that typically uses chords I IV V in any key. It’s useful to talk about chords as numbers or roman numerals because you might not always know what chords are called in any given key.


For guitar players, the chord shapes are often the same distance in frets from one another. Which fret and what string you start from will depend on what key it is you want to play in; knowledge of where your route notes are will come in handy. Learn how to find any note on your fretboard.

The blues is useful to learn because it teaches you how to improvise, play in different keys and practice different techniques whilst developing co-ordination rhythm and general musicality. 

I often teach the 12 bar blues to beginner guitarists. It teaches the beginner guitar player choice; which 12 bar blues variation it is you want to do? What sounds more interesting for the musicians around you? 

The Blues started to gain popularity since the 1900s. The blues is perhaps arguably popularised by films such as ‘Back to the Future’, with Johnny B Good. The Blues later developed in to the Rock & Roll that we are familiar with today by artists such as Jimi Hendrix and Eric Clapton.  

Play the 12 Bar Blues but in any key

The 12 bar blues also teaches how to play in different keys. Once you’ve learned a 12 bar blues sequence that doesn’t involve open strings, you’re then able to change keys by using the same pattern & by changing the tonic or ‘home’ note.  Using this method will allow you to play in different keys.

Aural training using the 12 Bar blues

When comparing guitar chords with piano chords the strings on the guitar dictates how the chord can be played. This is because of how the strings are tuned. For the guitar we sometimes have the following intervals I V VIII then the 7th note but depending on what string you start the chord from the intervals of the chord may be swapped. A C7 Chord for example would be intervals I V VII VIII on starting from string 5.

Whether the chord is from string 6 5 or 4 or in open position, the intervals can often be I V VIII then the (example) 7th note.

Eventually, you’ll learn recognise the aural distance for the I IV & V chords. With practice, you’ll be begin to notice which chord it is and whether or it’s a minor 7th or not. 

Blues chords typically include a 7th note.

By default, the 7th note is lowered by a semitone which is then added

Using the E major scale and counting 7 notes up from the tonic will provide you with a major 7th interval, D sharp.

Using the E minor scale and counting 7 notes up will result in a minor 7th interval, D natural. 

When ever we come across the 7th chord, such as C7, we’re referring to the minor 7th chord progression. By default, a chord written like: C7 will always assume the minor 7th interval and a chord like: Cmaj7 will of course refer to the major 7th interval. 

Notes of Chords E7 A7 and D7.

The E major chord has notes E B E G# B E. To transition from E major to E7 we add the flatten the 7th note or degree of the scale. 

In practical terms, we’re lifting off our 3rd finger to allow the D natural on string 4 to be heard. We now have the following notes: E B D G# B E.

For some, it’s easier to recognise the chord type rather than the tonic note of the chord. After a while, you’ll begin to recognise the root notes of the chord and then it’s chord type.

For the A7 chord, the notes of this chord are A D G C# E. Our 7th note is the note G natural. We’ve lowered the 7th degree by a semitone already. There are 3 sharps in the key of A major, F# C# G#. If we had kept the note G as a G# this would create the chord A major 7 because we’re in the key of A major. 

For the  D7 chord, the notes of this chord are D A C F#. In the key of D major our 7th degree is the note C. If we wanted to create a major 7th chord, we with raise the 7th a semitone or up one fret. D A C# F#.

12 Bar Blues in the key of E A & D major.

There are three ‘basic’ sequences to learn for the 12 bar blues that involves the open strings. These keys will be E Major (F# C# G# D#), A major (F# C# G#) and D Major (F# C#).

In the open position the D major key can be awkward but manageable. As guitar players we prefer to play the 12 bar blues in the key of D starting in position 5, string 5 or fret 10 string 6. A challenge or beginner guitar players because you have to learn how to co-ordinate your fingers to move from fret 2 to fret three and again from string to to string f

This method allows us to create a recognisable pattern on the fretboard rather than a mixture of sequences that include open and closed strings. It’s a far from ‘lazy’ approach because you have to stretch across the fretboard and include the use of finger 4.

Each key signature has it’s own challenges

The 12 bar blues in the key of E and A are beginner friendly because it’s a sequence that uses the same frets on different strings. The challenge here is that you have to transition from strings 4 to strings 3 whilst playing in time whilst co-ordinating your right hand to be in sync.

The ‘A major’ key in open position (frets 1 -5) is beginner friendly because whilst it uses a mixture of open and closed strings, you’ll practise switching from chords E5 to D5. A 5th chord includes the 5th degree of the scale, with no alterations needed hence perfect 5th.

The blues in the key of A involves the left hand changing chords & missing out string 4 whilst doing keeping time. It’s worth noting that you can play the 12 bar blues in the Key of E & A Major elsewhere on the fretboard too.

Whilst the blues in the key of E does include a mixture of open and closed sequences the B5 chord requires practice because you have to co-ordinate your first and third fingers.

The B5 chord requires notes on fret 2 & 4 on strings 5 and 4. Potentially confusing because you’ve been coordinating finger 3 to lift on and off after each pair of quavers. (1&)

The ‘One Four Five’ chords

Beginner guitar players often like to play in the key of E Major. It’s beginner friendly because the standard tuning of E A D G B E allows you to play open chords in the first position without having to barre.

  • In the key of E, the I IV V chords are E7 (I) A7 (IV) B7 (V). 
  • The key of E major has 4 sharps, F# C# G# D#. 

Chord I is the root note of the key it is you’re in. The IV represents the fourth degree of the scale or four notes away from chord 1. E (I) F G A (IV) B (V).

We use roman numerals instead of numerical numbers because these indicate which fingers the left hand should use. 

12 Bar Blues variations

You can of course adapt the basic 12 bar blues sequence to make it more challenging in any key. It should sound similar but a completely different challenge for the left and right hand. 

12 Bar Blues in the Key of C

The blues in the key of C uses chords C7 F7 and G7. C I F IV G V .

The chords C7 will include notes C E Bb C E. Although there aren’t any sharps or flats in the key of C major, to produce a minor 7th chord we have to lower the 7th degree. We therefor have to change the note B to a Bb. To create a major 7th chord we raise the note a semitone back to B natural.

The F7 chord is a barre chord. Whilst there aren’t any sharps or flats involved in the key signature guitarists face another challenge – the barre chord. There is however a solution. 

Both of these methods use the following notes: F C Eb A C F. In addition to being able to play the F7 chord in position 1 from string 6, you could play the F7 chord starting on fret 8 Using the same chord shape as you did for C7. You can now produce the chord F7 starting on string 5 fret 8. 

The same solution can be adopted for the G7 chord too. Whilst this chord is typically played on fret 3 with the root note on string 6, you could also use the shape of the C7 chord starting from fret 10 string 5. 

The above method allows you to play the 12 bar blues in the key of C using the same shape with each chord starting from string 5.

CAGED Guitar System

If the above confuses you, check out my ‘CAGED System for Guitar’, course.  Or continue reading the CAGED System for Guitar blog post.