In the last chapter we saw in detail how the three main open shapes are related to each other and how moving the notes in the same 'place' of the shape gives the same resulting chord type. This is obviously not a coincidence since all the three shapes share the same intervals in the same order.

But we could go one step further and say that they're actually exactly the same shape, only distorted by the way a guitar is tuned (in standard tuning, that is).

We know that a guitar is tuned in fourths except for the second string that is tuned a major third above the third string (G to B). This enables us to have the first and sixth string tuned to the same note and simplifies the fingerings of chords and scales since we just have four fingers to use but it distorts every chord and scale shape when they cross the second/third string .

If all the strings were tuned in fourths the shapes would look the same but we would need extra fingers to play them so we have to compromise but, knowing a few rules, we can easily move our shapes across the strings and approach the study of chords and scales in a different way.

I called these rules 'The Laws of Fretmapping' and they are the subject of another course, for now we'll just consider the first one:

“When moving a shape across the strings on a standard tuned guitar you move up one fret when you go from the third to the second string and you go back one fret when move from the second to the third.”

Let's see it in action starting from the E shape:

Shifting everything up one string, the two lowest fingers stay on the second fret while the highest moves up one fret when it goes from the third to the second string. Open strings remain open. Let's move everything up one more string to get to the D shape.

This time it's the middle finger that moves up one fret as it crosses over to the second string.

You can use this method anytime you want to move a chord or a scale or a lick or phrase across the strings in standard tuning.

But what about the other open shapes? They look so different! Could they be the same shape too? Let's go a step back and find out.

When we move from the E to the A shape we can add an open E on the sixth string, it's the fifth of the chord and it's the same note as the one on the first string. We can name this chord A over E (A/E) and we say it's a second inversion of an A major chord, which is a fancy way of saying that the fifth is the lowest note.

In the same way, when we move from the A shape to the D shape we can keep the open A (the fifth in the D chord) and we can add an F#, same note as the first string and also the major third. This is the first inversion of D major or D/F#.

But things really get interesting when we move the D shape: after we shift everything up, push the note on the second strings forward and add a low G (same as the first string) we get exactly the G major shape.

Moving the G shape up takes us to a C shape with a G note on top and at the bottom so it's a C/G chord, but the interesting thing is that you can see an E shape appearing on the three lowest strings.

And sure enough, if we shift everything up one last time, we get a F major that is really just an E shape with a barre at the first fret and the cycle is complete.

It may not be a very practical way to find this kind of basic chords but it may come in handy when we want to move smaller shapes (like 'Jazz' chords), scales or patterns across the strings.

It also shows how shapes on the guitar are not 'random', separate things but have very deep connections that may help you memorize them.

This is all for now on open chords and though there is a lot more to say and a zillion more shapes to discover I think there's enough material here to keep us busy for a while.

You can download the Open Chord Reference Pdfs here.