In the previous blog we looked at other scales. In this one we’ll revise intervals.
What Is An Interval?
Simply put an interval is the distance between two notes.
There are two types of interval: Melodic and Harmonic.
Melodic Intervals - These are intervals where the notes follow each other. They form a (part of a) melody.
Harmonic Intervals - These are intervals that are on top of each other. They are used for harmony.
Interval Qualities
Quality in this instances refers to whether an interval is either major, minor, perfect, diminished, or augmented.
A major scale will have the following intervals (going from the first note each time):
1 - Perfect unison
2 - Major 2nd
3 - Major 3rd
4 - Perfect 4th
5 - Perfect 5th
6 - Major 6th
7 - Major 7th
8 - Perfect octave
A minor scale will have the following:
1 - Perfect unison
2 - Major 2nd
3 - Minor 3rd
4 - Perfect 4th
5 - Perfect 5th
6 - Minor 6th
7 - Major 7th
8 - Perfect octave
Types Of Interval - Explained
A major interval features in a major scale.
A perfect interval is either unison, 4, 5 or octave. Perfect intervals appear in both major and minor scales.
A minor interval is one where a major interval is a semitone lower than a major scale.
A diminished interval is where a minor or perfect interval is a semitone lower.
An augmented interval is where a major or perfect interval is a semitone higher.
An interval that is no greater than an octave is classed as a simple interval. If an interval goes greater than an octave it becomes compound.
How To Work Out A Simple Interval
The most important things to remember when working out an interval is to start with the lowest note and to always use the major scale of that low note.
Here’s the method:
1. Starting with the lowest note count up the letter names counting the lower note as one. (It is important to count the letters as opposed to the pitch because using an enharmonic equivalent gives you a different interval name - even though it sounds the same. For example, G - C-sharp is 4 but G to D-flat would be 5 (I’ll go into more detail shortly)).
2. Next, using the lowest note as your tonic (first note of the scale) find out whether the upper note is in the major scale of that key. For example, a low note of G and a high note of B-flat would use the G major scale. Does B-flat appear in that? If it does, it’s a major third and if it doesn’t it’s a minor third. The answer is B-flat doesn’t appear in the G major scale therefore it is a minor third.
Examples Of Intervals Using G Major (The first note is always G)
Use the diagram above for reference - the number corresponds to the bar number.
1. Perfect Unison - Both notes are the same pitch.
2. Augmented Unison - The second note is a semitone higher but using the same letter which makes it augmented
3. Major Second - The second note appears in the G major scale.
4. Minor Second - The second note doesn’t appear in the G major scale. The note A is in the scale, A-flat is a semitone lower, thus making the interval a minor second.
5. Augmented Second - The second note doesn’t appear in the G major scale. The note A is in the scale, A-sharp is a semitone higher, thus making the interval an augmented second
6. Major Third - The second note appears in the G major scale. The note B is the third note making the interval a major third.
7. Minor Third - The second note doesn’t appear in the G major scale. The note B is in the scale, B-flat is a semitone lower making the interval a minor third.
8. Augmented Third - The second note doesn’t appear in the G major scale. The note B is in the scale, B-sharp is a semitone higher making the interval an augmented third. Pitch wise an augmented third will sound the same as a perfect fourth.
9. Perfect Fourth - The second note appears in the G major scale. The note C is the fourth in the scale making the interval a perfect fourth.
10. Diminished Fourth - The second note doesn’t appear in the G major scale. The note C is in the scale, C-flat is a semitone lower making the interval a diminished fourth. Pitch wise, a diminished fourth and major third will sound the same.
11. Augmented Fourth - The second note doesn’t appear in the G major scale. The note C is in the scale, C-sharp is a semitone higher making the interval an augmented fourth. This is also known as a tritone.
12. Perfect Fifth - The second note appears in the G major scale. The note D is the fifth note in the scale making the interval a perfect fifth.
13. Diminished Fifth - The second note doesn’t appear in the G major scale. The note D is in the scale, D-Flat is a semitone lower making the interval a diminished fifth.
14. Augmented Fifth - The second note doesn’t appear in the G major scale. The note D is in the scale, D-sharp is a semitone higher making the interval an augmented fifth.
15. Major Sixth - The second note appears in the G major scale. The note E is the sixth note in the scale making the interval a major sixth.
16. Minor Sixth - The second note doesn’t appear in the G major scale. The note E is in the scale, E-flat is a semitone lower making the interval a minor sixth.
17. Augmented Sixth - The second note doesn’t appear in the G major scale. The note E is in the scale, E-sharp is a semitone higher making the interval an augmented sixth. Pitch wise the augmented sixth and minor seventh will sound the same.
18. Minor Seventh - The second note doesn’t appear in the major scale. The note F# is in the scale, F (natural) is a semitone lower making the interval a minor seventh.
19. Major Seventh - The second note appears in the major scale. The note F# is in the scale making the interval a major seventh.
20. Diminished Seventh - The second note doesn’t appear in the major scale. The note F# is in the scale, F natural is a semitone lower making it a minor and because F-flat is a semitone lower than that, the interval is a diminished seventh.
21. Perfect Octave - The second note appears in the major scale. The note G is in the scale and as the pitch is an octave higher it makes the interval a perfect octave.
22. Diminished Octave - The second note doesn’t appear in the major scale. The note G is in the scale, G-flat is a semitone lower than G making it a diminished octave.
23. Augmented Octave - The second note doesn’t appear in the major scale. The note G is in the scale, G-sharp is a semitone higher than G making it a augmented octave.
Compound Intervals
A compound interval is greater than an octave. To work it out, lower the second (top) note by an octave to get your simple interval…then add the word compound in front.
Alternatively count the number of notes and use the bigger number. For example a major ninth is the same as a compound major second.
What Intervals Can Become?
The diagrams below will show you were the various interval qualities can go.
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