Intervals

What's an Interval?

An Interval is simply a way of describing the distance between two notes. We have already used some intervals in describing the Major Scale: Tone, Tone, Semitone, Tone, Tone, Tone, Semitone. The Tone and Semitone are Intervals. This is great for describing a small interval, but what if I wanted to describe the distance between C and F? I could say it was two and a half tones, or two tones and a semitone but there's an easier way.

Intervals follow a pattern, we're going to look at one octave for now which gives us...

Root, Minor 2nd, Major 2nd, Minor 3rd, Major 3rd, Perfect 4th, Augmented 4th/Diminished 5th, Minor 6th, Major 6th, Minor 7th, Major 7th and Octave.

Interval Name Shorthand Really Short-hand
Root Root Rt
Minor 2nd Min 2nd m2
Major 2nd Maj 2nd M2
Minor 3rd Min 3rd m3
Major 3rd Maj 3rd M3
Perfect 4th Per 4th P4
Augmented 4th or Diminished 5th Aug 4th / Dim 5th A4/d5
Perfect 5th Per 5th P5
Minor 6th Min 6th m6
Major 6th Maj 6th M6
Minor 7th Min 7th m7
Major 7th Maj 7th M7
(Perfect) Octave Oct 8ve

So, if we go back to the C to F jump; C is our Root Note, now we have to work out how far away F is from it...

Rt m2 M2 m3 M3 P4 A4/d5 P5 m6 M6 m7 M7
C C# D Eb E F F# G Ab A Bb B

So C to F gives us a Perfect 4th.

However F to C is NOT a Perfect 4th!

This is because our Root Note is now F and not C, so F to C would give us...

Rt m2 M2 m3 M3 P4 A4/d5 P5 m6 M6 m7 M7
F F# G Ab A Bb B C C# D Eb E

Which is an Interval of a Perfect 5th.

Using Intervals

We can use Intervals to create Scales and Chords, for example:

A Major Triad is always constructed of: Root, Major 3rd and Perfect 5th.

A Minor Triad is always constructed of Root, Minor 3rd and Perfect 5th.

Just as we can construct chords in this way, we can also construct Scales, like so:

Major Scale: Root, Maj 2nd, Maj 3rd, Per 4th, Per 5th, Maj 6 and Maj 7th

Natural Minor Scale: Root, Maj 2nd, Min 3rd, Per 4th, Per 5th, Min 6th and Min 7th
(Yes there's a Major 2nd. All will be explained when we look at Modes)

Why learn Intervals?

Intervals are extremely powerful in music, using them, we can start on any note and construct any chord or scale in any Key!

Let's look at a table of all possible Intervals...

Rt m2 M2 m3 M3 P4 A4/d5 P5 m6 M6 m7 M7
Ab A Bb B C C# D Eb E F F# G
A Bb B C C# D Eb E F F# G Ab
Bb B C C# D Eb E F F# G Ab A
B C C# D Eb E F F# G Ab A Bb
C C# D Eb E F F# G Ab A Bb B
C# D Eb E F F# G Ab A Bb B C
D Eb E F F# G Ab A Bb B C C#
Eb E F F# G Ab A Bb B C C# D
E F F# G Ab A Bb B C C# D Eb
F F# G Ab A Bb B C C# D Eb E
F# G Ab A Bb B C C# D Eb E F
G Ab A Bb B C C# D Eb E F F#

So if I wanted to work out the chord of A Minor, I'd start on the Root of A and then look for the notes that are at the Minor 3rd and Perfect 5th intervals from it, in this case: A, C and E. If I wanted to work out D Minor, I'd use the same Intervals but start on D this time, giving me: D, F and A.