Music intervals and degrees – complementary concept

In the article “What are augmented, diminished and perfect intervals?“, the “augmented” and “diminished” nomenclatures were used only for degrees 4th and 5th. However, we will now see that these denominations can be used for the other degrees as well.

In this case, for degrees that already have the denomination “major” and “minor”, the nomenclature “augmented” will mean a semitone above the major degree.  For example:

  • The major second degree is two semitones distance from the tonic. The augmented second degree three semitones distance from the tonic.
  • The major third degree is 4 semitones distance from the tonic. The augmented third degree is 5 semitones distance from the tonic.

Likewise, the “diminished” nomenclature means a semitone below the “minor” nomenclature. Examples:

  • The minor third degree is three semitones distance from the tonic. The diminished third degree is two semitones distance from the tonic.
  • The minor seventh degree is ten semitones distance from the tonic. The diminished seventh degree is nine semitones distance from the tonic.

Well, let’s summarize everything we’ve seen so far about degrees, to be clear.

If you still have difficulty thinking about tones and semitones, follow this study with the diagram below (where ST stands for “semitone”):

musical intervals degrees

For all degrees we will have the following distances:
Using the example of C as first degree:

  • Major 2nd – it is 1 tone front the tonic (D)
  • Minor 2nd – it is a half tone from the tonic (Db)
  • Augmented 2nd – it is 1 and a half tone from the tonic (D#)
  • Diminished 2nd – It does not exist

Observation: We chose to write the accidents related to D here because this is the note of the second degree in relation to C. We could have written, for example, Eb instead of D#, but this idea here is to think in D.

  • Major 3rd – it is 2 tones from the tonic (E)
  • Minor 3rd – it is 1 and a half tone from the tonic (Eb)
  • Augmented 3rd – it is 2 and a half tones from the tonic (E#)
  • Diminished 3rd – it is 1 tone from the tonic (Ebb)

Observation: Only to emphasize, we put all the accidents here related to E, because it is the third degree of C. For this Ebb appeared instead of D. This way, the logic is clearer. We will go on following this induction.

Other musical intervals

  • Perfect 4th – is 5 semitones from the tonic (F)
  • Augmented 4th – is 6 semitones from the tonic (F#)
  • Diminished 4th – is 4 semitones from the tonic (Fb)
  • Perfect 5th – is 7 semitones from the tonic (G)
  • Augmented 5th – is 8 semitones from the tonic (G#)
  • Diminished 5th – is 6 semitones from the tonic (Gb)
  • Major 6th – is 9 semitones from the tonic (A)
  • Minor 6th – is 8 semitones from the tonic (Ab)
  • Augmented 6th – is 10 semitones from the tonic (A#)
  • Diminished 6th – is 7 semitones from the tonic (Abb)
  • Major 7th – is 11 semitones from the tonic (B)
  • Minor 7th – is 10 semitones from the tonic (Bb)
  • Augmented 7th – is 12 semitones from the tonic (B#)
  • Diminished 7th – is 9 semitones from the tonic (Bbb)

Perhaps this definition seems a little unnecessary, after all, the augmented second degree is identical to the minor third degree, for example. This seems to be something created just to confuse our heads. Well, there is really no need to use this “augmented” and “diminished” nomenclature for degrees that already have the definition “major” and “minor”. However, it can help us.

Wait a minute, help?!

That’s right. Suppose that we want to build a chord that has a certain triad. Let’s build this triad with the diminished fifth instead of the perfect fifth, ok? Let’s say, C minor with diminished fifth. Since the chord is minor, we already know that the third degree is minor:

  • First degree: C
  • Minor third degree: Eb
  • Diminished fifth: Gb

This is our C minor with diminished fifth. Let’s say that now the band’s vocalist asks us to add the A note to that chord. Okay, we added the A note, but what are we going to call this chord?

The A note is the major sixth degree, so the chord will be called: “C minor with diminished fifth and major sixth”.

Ok, so far we haven’t applied any new concepts. This chord has only 4 notes and has a very large and complicated name. The most common tetrads we know have simple names (B minor seventh, F major seventh, etc.), but our Cm6(b5) is annoying to visualize because of the name.

So let’s apply the concepts we learned just now. The major sixth degree can also be called a diminished seventh degree.

This is interesting to observe, as our tetrad here would have basic degrees 1, 3, 5 and 7 (which is more common and easier to visualize than 1, 3, 5 and 6).

Great, but did that make anything easier in our nomenclature? Yes! Since we have a common tetrad (degrees 1, 3, 5 and 7) and two of these degrees are diminished (the fifth and seventh), it was decided that this chord would be called a “diminished chord“. That is, instead of “C minor with diminished fifth and major sixth” we have “C Diminished” (also called Cdim, or Cº).

That was just one application for this terminology. There are other situations in which you will see these concepts too, when we want to keep the focus on certain notes in some contexts, so it is good for you to know about this nomenclature so as not to be scared when you see “augmented third degree”, for example. It is just a matter of reference.

You also don’t have to worry about the chord notations we just showed, because in the next articles we will teach you in detail how to form chords and write their respective chord notations.

Go to: Chord notation

Back to: Module 2