Intervals
The distance between two notes — the unit every scale and chord is built from.
43 intervals
Unison and octave
The same note, and the same note twelve semitones away.
Seconds
A step. The smallest distance between two note names.
Thirds
What makes a chord major or minor.
Fourths
The perfect fourth, and the tritone that splits the octave.
Fifths
The strongest interval after the octave, and the two that surround it.
Sixths
A third turned upside down.
Sevenths
The note that turns a triad into a seventh chord.
Compound intervals
Wider than an octave. A ninth is a second, an octave up.
Diminished Ninth
9d · 12 semitones
Minor Ninth
9m · 13 semitones
Major Ninth
9M · 14 semitones
Augmented Ninth
9A · 15 semitones
Diminished Tenth
10d · 14 semitones
Minor Tenth
10m · 15 semitones
Major Tenth
10M · 16 semitones
Augmented Tenth
10A · 17 semitones
Diminished Eleventh
11d · 16 semitones
Perfect Eleventh
11P · 17 semitones
Augmented Eleventh
11A · 18 semitones
Diminished Twelfth
12d · 18 semitones
Perfect Twelfth
12P · 19 semitones
Augmented Twelfth
12A · 20 semitones
Diminished Thirteenth
13d · 19 semitones
Minor Thirteenth
13m · 20 semitones
Major Thirteenth
13M · 21 semitones
Augmented Thirteenth
13A · 22 semitones