Intervals can also be Inverted ( a fancy name for turning them upside down ) . If we take the Major 3rd interval from the note C to E and turn it upside down so that the E note is on the bottom and the C note is on top, we have inverted the Major 3rd interval. The important thing to note, is that we must now use the Major scale of the bottom note when working out the inverted interval.

We must now work out the Interval using the E Major scale. If we count the alphabet letters first from E to C we can determine that it is a 6th, ( E, F, G, A, B, C ) as there are 6 letters from E to C. The E Major scale, however, consists of the notes E F# G# A B C# & D# . Because the note C is a semitone lower than the C# found in the E Major scale the interval will be classified as a Minor 6th.

To work out the Type of Interval after it has been inverted, just subtract the original interval from 9. This means that :-

• 2nds will become 7ths when Inverted.
• 3rds will become 6ths when Inverted.
• 4ths will become 5ths when Inverted.
• 5ths will become 4ths when Inverted.
• 6ths will become 3rds when Inverted.
• 7ths will become 2nds when Inverted.

Some rules to help with the Quality of Inverted Intervals are:-

• Major Intervals when inverted become Minor Intervals.
• Minor Intervals when inverted become Major Intervals.
• Perfect Intervals will remain Perfect Intervals.
• Diminished Intervals when inverted become Augmented Intervals.
• Augmented Intervals when inverted become Diminished Intervals

Examples of Inverted Intervals

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

So to summarise what happens to Intervals after they are Inverted :-

• Major 2nd Intervals become Minor 7th Intervals.
• Minor 3rd Intervals become Major 6th Intervals.
• Diminished 5th Intervals become Augmented 4th Intervals.
• Perfect 5th Intervals become Perfect 4th Intervals.
• Major 6th Intervals become Minor 3rd Intervals.
• Minor 7th Intervals become Major 2nd Intervals etc etc...