• Exposed: The Difference Between The Minor Third And Augmented Second Interval

We’ll be learning the difference between the minor third and augmented second interval in this lesson.

Although the intervals below:

C-Eb:

C-D#:

…sound alike when played, they are entirely different intervals and we’ll be looking at the theoretical reasons why they are different.

But before we do so, let’s refresh our minds on the minor third and augmented second interval.

“A Refresher On The Minor 3rd And Augmented 2nd Interval”

An interval is a product of the relationship between two notes that are heard together or separately. The minor third and augmented second intervals are produced by the relationship between two notes.

The Minor Third Interval

It’s easier to form the minor third interval when you’re familiar with the major third interval. So, let’s talk about the major third interval, then derive the minor third interval from it.

“The Major Third Interval”

When the first and third tones of the major scale in any key are played or heard together, a major third interval is produced.

Using the C major scale (as a reference):

…the major third interval can be formed by the relationship between the first tone (C):

…and third tone (E):

So, C-E:

…is a major third interval.

“Here’s How To Derive The Minor Third Interval From The Major Third Interval…”

Lowering the upper note of the major third interval by a half-step produces the minor third interval. The upper note of the C-E major third interval:

…which is E:

…can be lowered by a half-step (to Eb):

…to produce C-Eb:

…a minor third interval.

“Here Are All The Minor Third Intervals On The Keyboard…”

C minor third:

C# minor third:

D minor third:

Eb minor third:

E minor third:

F minor third:

F# minor third:

G minor third:

G# minor third:

A minor third:

Bb minor third:

B minor third:

Let’s check out augmented second intervals.

Attention: To learn more about intervals, how they are applied in chord formation, and other important concepts, I recommend that you get our 500+ page course: The “Official Guide To Piano Playing.” If you’re interested,click here to let us know.

The Augmented Second Interval

When the major second interval is made larger (or augmented) by a half-step, this produces the augmented second interval.

“So, What’s A Major Second Interval?”

A major second interval is produced when the first and second tones of the major scale in any key are played or heard together.

In the key of C major:

…the first tone (C):

…and second tone (D):

…when played or heard together (as “C-D”):

…produces the C major second interval.

“Now, What Is An Augmented Second Interval?”

An augmented second interval is formed by making the major second interval larger by a half-step. For example, making the C major second interval (C-D):

…larger by a half-step produces C-D#:

…which is an augmented second interval.

“Check Out All The Augmented Second Intervals On The Keyboard…”

C augmented second:

Db augmented second:

D augmented second:

Eb augmented second:

Fb augmented second:

F augmented second:

Gb augmented second:

G augmented second:

Ab augmented second:

A augmented second:

Bb augmented second:

Cb augmented second:

Now that we’ve refreshed our minds on the minor third and augmented second interval, let’s look at the differences between these intervals.

Attention: To learn more about intervals, how they are applied in chord formation, and other important concepts, I recommend that you get our 500+ page course: The “Official Guide To Piano Playing.” If you’re interested,click here to let us know.

The Minor Third Interval vs Augmented Second Interval

The minor third and augmented second interval sound alike when played. Looking at them on the keyboard, you can’t tell one from the other, except they are spelled:

C-Eb:

…is a minor third interval.

C-D#:

…is an augmented second interval.

Although it’s so easy to think that both intervals are the same, there are important differences between them and we’ll be ending this lesson by focusing on those differences.

Difference #1 – In Size

The augmented second and minor third interval differ in size. The former is a second interval while the latter is a third interval.

C-D# (encompasses two alphabets: C and D)

C-Eb (encompasses three alphabets: C, D, and E)

In the formation of chords, the use of second intervals produces secundal harmony while the use of third intervals in the formation of chords produces tertian harmony.

Following the traditional principles of chord formation, third intervals (and not second intervals) are used in chord formation. This explains why the minor third interval is commonly used.

Summarily, minor third intervals differ in size from augmented second intervals and because augmented second intervals are second interval, they are NOT commonly used in chord formation.

Attention: To learn more about intervals, how they are applied in chord formation, and other important concepts, I recommend that you get our 500+ page course: The “Official Guide To Piano Playing.” If you’re interested,click here to let us know.

Difference #2 – In Quality

The augmented second interval and the minor third interval differ in quality:

The augmented second interval is an augmented interval.

The minor third interval is a minor interval.

Augmented intervals and minor intervals are two different interval types. Augmented intervals (when played or heard) have the tendency to move to a more stable interval or chord and this is because they don’t sound agreeable when played/heard.

Another classic example of an augmented interval is the augmented fourth interval (aka – “tritone”). The tritone has its special place in harmony because of its distinct harshness.

Minor intervals are a lot more stable and are used in the formation of major, minor, dominant chords, etc.

“In Summary…”

Intervals are the building blocks of chords. The difference between the augmented second and minor third intervals is in the application of intervals during chord formation.

…may sound like a minor chord, however in actuality, it is not a minor chord because it doesn’t have a third tone.

The chord above:

…and the C minor chord:

…are as different as the augmented second and minor third intervals, notwithstanding that they sound alike.

Final Words

From what we’ve covered in this lesson, you can clearly see that the minor third and augmented second intervals are different.

In a subsequent lesson, we’ll learn more about minor third intervals and how they are used to determine chord quality.

See you in a subsequent lesson.

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Chuku Onyemachi

Head of Education at HearandPlay Music Group
Onyemachi "Onye" Chuku (aka - "Dr. Pokey") is a Nigerian musicologist, pianist, and author. Inspired by his role model (Jermaine Griggs) who has become his mentor, what he started off as teaching musicians in his Aba-Nigeria neighborhood in April 2005 eventually morphed into an international career that has helped hundreds of thousands of musicians all around the world. Onye lives in Dubai and is currently the Head of Education at HearandPlay Music Group and the music consultant of the Gospel Music Training Center, all in California, USA.

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1 Femi

You haven’t broken it down yet. You just said they are different. What I see is the fact that the minor third interval is the same as augmented second interval. By this, you haven’t taught me anything new. Both are still the same. Minor third interval(C and Eb), augmented second interval(C and D#). Denotatively, hey are the same and I think the quality and difference is in movement rather than voicing coz when played with the perfect fifth, they sound the same unless the fifth is the degree is diminished.

But what do I know? I would like you to break it down completely so students like us will know the striking and stack differences. Thanks

2 Chuku Onyemachi

Both intervals sound alike, no doubt. However, they differ in size and quality and this means a lot when chord formation is concerned.

All these are explained in this blog.