Information about the augmented ninth interval

Name

This interval is called: Augmented ninth

Abbreviation

You can use the somewhat shorter name "A9" to indicate a Augmented ninth.

Chord name

Sharp nine

Construct

How to build a augmented ninth interval?

To construct an interval correctly you must always use two steps.

  1. Count the amount of naturals used
  2. Count the steps between de two notes

At first, and with easy intervals, this may seem unnecessary, but when advancing to more dificult intervals and musical keys they will become more mandatory.

The following example is for a augmented ninth from C3. Outcome: D#4

1.
A Augmented ninth uses 9 naturals.
Example: C3 D3 E3 F3 G3 A3 B3 C4 D4
2.
A Augmented ninth has 15 semitones between the notes.
Example: C3 C#3 D3 D#3 E3 F3 F#3 G3 G#3 A3 A#3 B3 C4 C#4 D4 D#4

Cheatsheet

Tranposed for each note

You can use the following cheatsheet to check the Augmented ninth for each root note.
Cb3 ↠ D4
C3 ↠ D4
C3 ↠ D#4
C3 ↠ D4
C#3 ↠ D##4
C3 ↠ D4
Db3 ↠ E4
D3 ↠ E4
D3 ↠ E#4
D3 ↠ E4
D#3 ↠ E##4
D3 ↠ E4
Eb3 ↠ F#4
E3 ↠ F4
E3 ↠ F##4
E3 ↠ F4
E#3 ↠ F###4
E3 ↠ F#4
Fb3 ↠ G4
F3 ↠ G4
F3 ↠ G#4
F3 ↠ G4
F#3 ↠ G##4
F3 ↠ G4
Gb3 ↠ A4
G3 ↠ A4
G3 ↠ A#4
G3 ↠ A4
G#3 ↠ A##4
G3 ↠ A4
Ab3 ↠ B4
A3 ↠ B4
A3 ↠ B#4
A3 ↠ B4
A#3 ↠ B##4
A3 ↠ B4
Bb3 ↠ C#5
B3 ↠ C5
B3 ↠ C##5
B3 ↠ C5
B#3 ↠ C###5
B3 ↠ C#5