Salford Piano Studio

When we move the bass note of an interval an octave higher, we have **inverted **it.

Since there are only two notes in an interval, there is only one inversion possible.

For Example, let’s take a **Third **(C-E):

By moving the C an octave higher, we now have a **Sixth** (E-C):

Let’s go over the different inversions.

**Interval Pairs**

There’s perfect symmetry in interval inversions – pairs of intervals invert one into the other.

As always, we start with C to make it simple.

**Second/Seventh**

A Second inverts to a Seventh.

**C**–**D **(2nd)** **| **D**–**C **(7th)

A Seventh inverts to a Second.

**C**–**B **(7th)** **| **B**–**C** (2nd)

**Third/Sixth**

A Third inverts to a Sixth.

**C**–**E **(3rd)** **| **E**–**C** (6th)

A Sixth inverts to a Third.

**C**–**A **(6th)** **| **A**–**C** (3rd)

**Fourth/Fifth**

A Fourth inverts to a Fifth.

**C**–**F **(4th)** **| **F**–**C** (5th)

A Fifth inverts to a Fourth.

**C**–**G** (5th) | **G**–**C** (4th)

**Unison/Octave**

Note how we cannot invert a Unison or an Octave.

A Unison will remain exactly the same, as it’s made of the same two notes.

If we try to invert an Octave, it will result in a higher Octave.

**Interval Quality**

So far, we’ve dealt with generic interval inversions.

Let’s examine the interval quality as we invert.

**Perfect Intervals**

Perfect Intervals remain the same.

A Perfect 4th inverts to a Perfect 5th and vice versa

**Major/Minor**

Major intervals invert into Minor intervals and vice versa.

For example, a Major Third inverts to a Minor Sixth.

**C**–**E **(M3) | **E**–**C** (m6)

**Augmented/Diminished**

Like Major and Minor intervals, Augmented and Diminished intervals invert one into the other.

For example, Diminished Fifth inverts to an Augmented Fourth.

**C**–**G♭** (D5) | **G♭**–**C **(A4)

**Example**

Beethoven’s 3rd Piano Sonata starts with thirds in the right hand.

In the two bars below, he ends the phrase with a Sixth.

The last two intervals are an inversion: Major 3rd – Minor 6th.