12 Bar Blues, Rock n Roll & I IV V

In the post What do I IV V (1 4 5) chords mean and why should you care? we learnt how I IV V chord harmony works, what songs they’re used in and how to transpose songs between keys. Now we’re going one step further down this path and looking at how the I IV V chords relate to Blues and Rock n Roll.

There are thousands of Blues and Rock n Roll songs using I IV V chords and something called the 12 Bar Blues. The 12 Bar Blues is a 12 bar song structure that looks like the diagram below.

12 Bar Blues I IV V Structure

In the key of A it translates to the following chords. To give this a more “bluesy” flavour try playing all chords as (dominant) 7th chords.

12 Bar Blues in A

Mp3 Track

12 Bar Blues in A Strumming | Download
Listen to the audio example to hear the 12 Bar Blues in A strumming pattern and structure.

This 12 bar structure is used in the following well know blues songs:

  • Boom Boom
  • Crossroads
  • Killing Floor
  • Little Red Rooster
  • Love in Vain
  • Red House
  • Rock Me Baby
  • Shake Your Moneymaker
  • Sweet Home Chicago
  • The Thrill is Gone
  • Walking Blues

The 12 Bar Blues is such a simple and effective song structure that it was adopted for many early 50s rock n roll songs including:

  • Blue Suede Shoes
  • Great Balls of Fire
  • Good Golly Miss Molly
  • Hound Dog
  • Johnny B Goode
  • Long Tall Sally
  • Mess Around
  • Mustang Sally
  • Rock round the Clock
  • Route 66
  • What I’d Say

The 12 bar blues chord structure is also used in later songs including:

  • Ça Plane Pour Moi – Plastic Bertrand
  • Green Onions – Booker T & The MGs
  • Give Me One Reason – Tracey Chapman
  • Lets Stick Together – Brian Ferry
  • Revolution – The Beatles
  • Real Wild Child – Iggy Pop
  • Rock n Roll – Led Zeppelin
  • Southbound – The Allman Brothers
  • Why Cant We Do It In The Road – The Beatles

Obviously all these songs aren’t in the key of A. In What do I IV V (1 4 5) Chords Mean and Why Should You Care? we looked at transposing between different keys with a table listing the I IV V chords in various keys. On guitar there is another easy way of working out the I IV V chords of different keys.

The trick to this is using the pattern shown below on the low E (6th) and A (5th) strings of the guitar. For example if you know the song is in the key of G find the G note on the E (6th) string. Then if you go across to the same fret on the A (5th) string this will be the root note of the IV (C) chord and moving 2 frets up on the A (5th) string will be the root note of the V (D) chord. Pretty simple!

145_rootsG

145_rootsA

Of course this now means that you have to learn the notes on the E (6th) and A (5th) strings. While this may seem daunting at first it is essential to know the location of these notes for this exercise. Plus learning these notes will come in handy for playing bar (barre) chords and learning scales for guitar solos in different keys. To help make this task easier use the diagram below to learn and memorise these notes.

Guitar Neck Notes

A good practice exercise to help learn these notes on the guitar neck is to work out the I IV V root note locations for the following keys. Try doing this once or twice a day until you can do it without using the diagram of the notes on the guitar neck.

145_chords

SPREAD RHYTHM PATTERN
Now we know how to find the I IV V root notes on the guitar neck we’ll look at a pattern to play in these locations. The “spread rhythm” is a pattern used in blues and early rock n roll music especially by Chuck Berry. It is called a “spread rhythm” as it requires you to spread your fingers on the guitar neck to play it.

For a 12 bar blues in the key of A the root note of the A chord is on the 5th fret of the low E (6th) string. Place finger 1 on the root note of A on the 5th fret. Then spread finger 2 out to the 7th fret on the A (5th) string. For the entire spread rhythm pattern you just play just two strings. Pluck this shape 2 times then stretch finger 4 to the 9th fret on the A (5th) string and play this twice.

blues_Aspread_1bar

bluesa_spread1bluesa_spread2

You then simply alternate back and forth between the 2 shapes. Have a listen to the audio sample to hear how this sounds.

Mp3 Track

A Spread Rhythm Pattern | Download
Listen to the audio example to hear the spread rhythm pattern.

To play the D (IV) and the E (V) versions simply change the pattern to the other root note locations as shown in the guitar tab below for the 12 bar blues.

blues_Aspread

Mp3 Track

12 Bar Blues in A Spread Rhythm Pattern | Download
Listen to the audio example to hear the spread rhythm pattern in a 12 Bar Blues in A.

To play this pattern in different keys simply shift it around to start on the matching note for the key. So if you want to play a 12 bar blues in G move the pattern so it starts with finger 1 on the 3rd fret of the E (6th) string or if you want to play blues in B start with finger 1 on the 7th fret of the E (6th) string.

So now you know how to play a basic blues pattern that can also be used in hundreds if not thousands of rock n roll songs. Plus you know now how simple it is to change keys by simply shifting the pattern up and down the guitar neck. A big part of guitar playing is all about learning patterns so if you can get this concept under your fingers you’ll have great foundation for learning other aspects of guitar playing such as bar chords and scales for playing guitar solos