What Is a Music Interval? (The Complete Idiot’s Guide)

• Looking to grasp the basics of music intervals?
• Detailed explanations and all your commonly asked questions answered

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An interval is one of the basic building blocks of “western” music theory and refers to pitch differences between two notes.

Pitch is the frequency of a note. If you double the frequency, it is the same note but an octave higher. The octave is an interval.

The space within an octave is divided into 12 notes. As you can imagine, this creates a lot more intervals.

Let’s take a closer look!

What Is A Music Interval?

All western music is based on those 12 different notes we discussed in the introduction.

Need a quick revision of the notes? We got you!

Music Notes

We are working with C, D, E, F, G, A, and B. Those are the white keys on our keyboard below. Additionally, there are black keys between some of those notes, making a total of 12 before it starts all over again.

There are always two different names for the notes of the black keys, which has something to do with the context of those notes.

If that doesn’t make too much sense right now, that’s fine. Just accept that there are 2 different names for the same note: one with a # (sharp) and the other with a b (flat) behind it.

Side note: Trying to refer to those symbols? For # you use the term ‘sharp’ and for a b the term ‘flat’.

C# = “C sharp”
Db = “D flat”

Every melody and harmony in western music is based on those notes – from Taylor Swift to Beethoven and from Mozart to Kendrick.

Note Intervals

The distance between one key on the keyboard to a key right next to it is called a minor second, also often referred to as a semi-tone.

It is the smallest unit we deal with looking at intervals, and it doesn’t matter if the keys change colors or not. G to Ab is a semi-tone, and so is E to F.

Now, let’s take a look at the different note intervals within one octave, including their distance in semi-tones, as well as an example:

Name	Semi-tones	Example
minor second	1	D – Eb
major second	2	G – A
minor third	3	F – Ab
major third	4	G – B
perfect fourth	5	B – E
tritone	6	C – F#
perfect fifth	7	F – C
minor sixth	8	D – Bb
major sixth	9	E – C#
minor seventh	10	A – G
major seventh	11	C – B

Feel free to reconstruct the intervals on the keyboard above or count the semi-tones to better understand what is happening.

Scales & Chords

You might have noticed the terms “major” and “minor “in some of the intervals. And surprise, there is a connection between those intervals and the corresponding scales or chords. 

We will examine this relation on the C major scale: it uses only the keyboard’s white keys, so it goes C, D, E, F, G, A, B.

Now, let’s look at the interval between the different notes of the scale and the root note C.

C – D: major second
C – E: major third
C – F: perfect fourth
C – G: perfect fifth
C – A: major sixth
C – B: major seventh

Apart from the perfect 4th and perfect 5th interval, the scale is constructed using only “major scale intervals”.

Taking this a step further: to build a major triad you use the root note, together with the major third, and the perfect fifth interval to the root note.

Here are a few examples:

Chord	Notes	Major Third	Perfect Fifth
C major	C – E – G	C – E	C – G
D major	D – F# – A	D – F#	D – A
Bb major	Bb – D – F	Bb – D	Bb – F

If that works with major, it must work with minor, right? Yes! (almost…)

Let’s use D minor as an example scale for this one. D’s natural minor scale notes are D, E, F, G, A, Bb, and C.

Side note: Apart from the natural minor, there are also harmonic and melodic minor scales.

As you can see below, for the minor scale, you use all the minor scale intervals except for the minor second. Counterintuitively, the minor scale also uses the major second. 

D – E: major second (!)
D – F: minor third
D – G: perfect fourth
D – A: perfect fifth
D – Bb: minor sixth
D – C: minor seventh

Minor chords are constructed with the root note along with the minor third and perfect 5th interval to the root note.

Here are again a few examples for you:

Chord	Notes	Minor Third	Perfect Fifth
C minor	C – Eb – G	C – Eb	C – G
F minor	F – Ab – C	F – Ab	F – C
A minor	A – C – E	A – C	A – E

Side note: Did you notice? Neither scale makes use of the tritone interval. It’s not a very harmonic interval and can sound rather unpleasant to our ears.

More Complex Intervals

Apart from the “basic” major and minor scale intervals, there are a few more complex types.

Compound Intervals

Compound intervals are larger than one octave. They are constructed with an octave + another interval. A ninth would therefore be a compound second, a twelfth a compound fourth.

Augmented and Diminished Intervals

In the beginning, we covered that depending on the context, the same note can have two different names for example, G# and Ab. In a similar but more complex way, intervals can also have different names.

In this case, the term diminished makes the interval a semi-tone smaller, and the term augmented one semi-tone larger.

Let’s try to dissect this with an example:

The interval C – A is a major sixth. Depending on the harmonic context, you could also find the interval C – A#. Now audibly, this is a minor seventh. It sounds like a minor seventh because A# is just another name for Bb.

But theoretically, you call the interval C – A# an augmented sixth because it is the altered sixth note of the scale.

History and Physics

Yeah, if you just want to skip ahead to how to identify the intervals, I don’t blame you… 

So, where does this system come from, or who came up with it? 

The general division of the different intervals has its origin in physics or nature. When you play a note on an acoustic instrument, you don’t only hear that specific note but many different notes above with it.

Those tones are called overtones or harmonics.

These overtones stand in a particular physical relation to the root note. To better understand this, think of any stringed instrument. Exciting the string will cause it to vibrate at a specific frequency and generate a note.

Now, if you shorten the string by 1/2 it will vibrate at a different frequency, exactly one octave higher.

This relation of 1:2 can also be found in the first overtone, one octave above the root. To continue, you could look at the relation between this overtone and the next, which is 2:3 resulting in the perfect 5th interval.

From here on, it gets a lot more complex and very mathematical.

Unfortunately, simply stacking those frequency relationships doesn’t quite work out within a harmonic and pleasant-sounding musical system.

Throughout history, there were different approaches to the maths behind our music theory, compromises had to be made, and some of the “natural intervals” had to be slightly adjusted.

If you want to get into this, here is a short list of terms that will lead you right into the lion’s den:

• Syntonic comma
• Pythagorean comma/temperament (yup, same guy)
• Werckmeister temperament
• Well-tempered tuning

Identifying Music Intervals

So how do you identify music intervals?

The first step is understanding the theoretical concepts of intervals we covered above. However, the specific application or approach may vary and depend on which instrument you play or if you can read music. 

Once you are comfortable with the general idea of intervals, the real fun begins:

Identifying them by ear.

It will take a lot of practice and can sometimes be quite frustrating if you are just starting. But it is great training for your ears (and a big flex).

There are many (free) tools online for you to practice with. You can start small and learn to choose between 2 intervals and slowly build up from there.

In the beginning, it is easier to listen to the notes one after the other rather than simultaneously. Mainly because this way, you can make use of reference songs or motifs.

Find a song you like, that starts with that specific interval or makes use of it at a certain point and you will be able to identify the interval more easily.

There are long lists of references you can use. Since you are already here, I will give you my personal favorites:

Favorites:

minor second: Pink Panther / Jaws
major second: Lord of the Rings – main theme
minor third: Greensleeves / Seven Nation Army
perfect fourth: Ambulance / Here Comes The Bride
tritone: The Simpsons

Star Wars:

perfect fifth: Star Wars – main theme
minor sixth: Star Wars – Padme’s theme
major sixth: Star Wars – Leia’s theme

Classics:

minor seventh: ABBA – The Winner Takes It All
major seventh: A-ha – Take On Me
octave: Somewhere Over The Rainbow

Now you are ready to practice!

If you’re comfortable with the note intervals, try playing them simultaneously and then move on to chords.

FAQs

What Are The Intervals In Music?

An interval describes the distance between two notes.

How Do You Identify Intervals In Music By Ear?

Once you are comfortable with the theory behind it, start with a small number of intervals and try using reference songs.

What Are Compound Intervals?

Compound intervals are larger than an octave and constructed from an octave and another interval.

Before you head off, check out our post on all the wonderful types of triads.