​​​​Intervals 7th Chords

Last Updated August 16, 2019

What are intervals?

Intervals are the measurements of space in between notes. Space as in, how many notes away one note is from another. From previous lessons we know all about the chromatic scale. By now we know that the distance between one fret to the next is a semi-tone and the distance between two is called a tone. We can think of intervals as a fancy version of this.

First let’s list the Intervals in order,

Minor 2nd
Major 2nd
Minor 3rd
Major 3rd
Perfect 4th
Augmented 4th or Diminished 5th
Perfect 5th
Minor 6th or Augmented 5th
Major 6th
Minor 7th
Major 7th

Looking at that we can see some of those have a ‘or’ meaning they have different names but are the same thing. There is a reason why and when to use either, but to be perfectly honest you don’t need to know that and only the most anal of musicians would scold you for picking the wrong one. Pick which ever you like. But for loose guidance if we are talking about a flat note use diminished and if we are talking about a sharp note use augmented. But that opens the question when to use a sharp or a flat, again there is a reason……lets move on shall we!

Starting with the root, each interval there after is the distance of one semi-tone, or on your guitar one fret, or on a piano, one key. So lets try writing it all out using C as the root. This is what we get,

C   Root
C#  Minor 2nd
D   Major 2nd
Eb  Minor 3rd
E   Major 3rd
F   Perfect 4th
Gb  Diminished 5th
G   Perfect 5th
Ab  Minor 6th
A   Major 6th
Bb  Minor 7th
B   Major 7th

NOTE: Sometimes you might hear or see ‘4th’ or ‘5th’ on its own. When people write or say this they mean perfect 4th/5th.

After B we get back to C again.

So we can say, a major 3rd from C is an E.

You might be wondering why not just number them from 1-12 and call them 1 step, 2 step etc. To be perfectly honest I haven’t a clue. Why is ‘Phone’ not spelt ‘Fone’? it’s just the way it is and was, and nobody wants to mess with it.

Let’s not be the first!

Okay, so what’s the point of all this?

The point is we can use these intervals to build chords and scales and to understand what we are playing. Lets look at the major chords we already leant.

ALL major chords are made from the following,

Root – Major 3rd – Perfect 5th

This is called a major triad. Triad because its made from three notes.

Okay then, lets choose to make a C major chord. So starting with C as the root we need to plug in a major 3rd and then a perfect 5th. If we do that we end up with this,

C  Root
E  Major 3rd
G  Perfect 5th

So we know that to make a C major we need to use a C, E and a G. Lets look at the old C major diagram we already know:

According to the formula we just learnt all the notes we’ve been playing in this C major should be either C, E or G.

Let’s go through the chord string by string. The first note we play is the 3rd fret on the A string which is a C. Being the root its the first note of the chord which is correct. Next is the D string 2nd fret which is an E, that’s correct we want ‘E’s. Next is the g string played open, which is the G we’re looking for. Next is the b string 1st fret which is another C note. And lastly the top e string open, which is another E note. So as we can see all the notes in the chord of C major is C, E and G just like the formula said!

Lets look at A major

A  Root
C# Major 3rd
E  Perfect 5th

Now remember the A mjor chord we’ve been playing? Go through each note and you will see each note is either A, C# or E.

So now we know how all those major chords we’ve been playing are made. Let’s have a look at how minor chords are made using A minor as a example,

A  Root
C  Minor 3rd
E  Perfect 5th

We can see the difference between a Major and Minor chord is we replace the major 3rd with a minor 3rd. And we know the difference between a major and minor 3rd is only 1 semi-tone. Let’s look at the diagrams for A major and A minor again side by side:


Let’s focus on the b string. A major has a C# that note on the 2nd fret. If we look at the A minor diagram we can see that little dot has been moved back 1 fret. We’re changing the major 3rd for a minor 3rd. And just like that we’ve created a minor chord. Have a look at the E major and minor chords and the D major and minor chords, you can see the same thing happen.

Remember back in the Minor chords lesson we used new barre chords to play the C minor and G minor? This is because if we take the normal open chord versions of C and G major and try to shift that major 3rd back a semi-tone, what we get is a very difficult chord to play. That is the reason why we rearrange our fingers about to a more comfortable shape.

So lets recap,

Major chord = Root, major 3rd and 5th

Minor chord = Root, minor 3rd and 5th

So what about other chord types?

Now we will introduce the ‘7’ chords. There are three main types of these chords. Called the dominant 7th, major 7th and the minor 7th. Lets have a look at how to play these chords, boiled down to their essence they can be thought of like this,

Dominant 7th – same as a major chord, but stick in a minor 7th.
Major 7th – same as a major chord, but stick in a major 7th.
Minor 7th – same as a minor chord, but stick in a minor 7th.

Lets use ‘A’ as the root to explore this. Minor 7th from an ‘A’ is a G note and a major 7th a G#.

So to play a A dominant 7th we just need to play the regular A major chord but just plug in a G note somewhere in there. To play a A major 7th we need too plug in a G# somewhere in there. And to play a A minor 7th we would need to play a A minor but work in a G note somewhere.

Below are the diagrams for all these A chords we have be introduced to now:


You will notice that a dominant 7th will normally be labelled as the root plus the 7, in this case A7. A major 7th will normally have a big capital ‘M’ and a minor 7th a lower case ‘m’.

At the moment it’s not important that you should be able to produce all these chords on the fly instantly just by knowing the intervals that make up the chord. But it is helpful to realise how these chords are made in case your mind may slip and you forget how that box diagram looks in your head. When that happens you can build the chord yourself or even try to build the chord in different positions and shapes if you are bored of the old ones.

But for now here is a complete set of all these new 7th chords for you too see and memorise!


That’s a lot to digest! Don’t feel like you have to learn all of them. A tip is to learn the ‘A’ and ‘E’s only and use barre chords for the rest of them! If you’re not sure what I mean have a noodle at the barre chords lesson to see for yourself.

These 7th chords tend to have a more jazzy sound and are prevalent in jazz and blues music. Try experimenting playing a progression using only these 7th chords it will have a completely different feel and vibe, however its up to you to decide if you like the sound of this or not.

And finally before we go we have one last chord type to introduce. It’s called the diminished chord and is played like a minor chord only we use a diminished 5th instead of a perfect 5th. The simplest way to learn these chords is to play the A minor then turn them into a diminished chord by moving that 5th back a fret. Then we can turn this chord into a the other diminished chords we need by turning it into a barre chord.


These chords have a slightly odd dissonant sound that sometimes sounds ‘wrong’ and out of place and as you can guess aren’t used that often.

Have a bash at all these new chords and don’t worry so much about remembering all of them, you can always look them up later.

Key points to remember!

  • Intervals mesure the distance of a note from it’s root.
  • We can use intervals to explain how chords and scales are made.
  • Understanding intervals helps us understand how to play 7th chords.
  • Understanding intervals helps us play new chords and scales faster.