Chromatic Intervals Worksheet

[Richard_close2u]

@Rumil

I’m missing the 2nd diminished interval .

Hi Edgar.
Intervals can be a little bit tricky to learn and understand initially. I wrote a full topic recently prompted by a discussion and set of questions elsewhere in the Community. That topic is here: Intervals, scale degrees and more

In one post I wrote the following:

It is worth mentioning that the naming system relies on assigning each of the intervals an ordinal number (second, third, fourth, fifth, sixth, seventh) relative to the first or starting note. The numbering stems from the fact of having seven alphabetical letters in use for musical notes. A – B – C – D – E – F - G. Any interval describing the distance between A and C must be some type of third since making A the first letter automatically fixes C as the third letter.

Each interval is also assigned a quality.
The unison, fourth, fifth and octave are perfect (we can think of them as sounding ‘perfect’ with the first note - they are consonant with it).
The second, third, sixth and seventh are major.
Perfect intervals and major intervals in total make up all seven intervals contained within a major scale.

• Unison (= root)

• Major second

• Major third

• Perfect fourth

• Perfect fifth

• Major sixth

• Major seventh

• Octave (= root)

Any interval whose distance from the start note is one semitone more than these perfect and major intervals is described as augmented.

Minor is the assigned quality for intervals whose distance is one semitone less than major intervals. For major and minor intervals, a simplistic view would be to think of them as ‘big’ versions / ‘small’ versions of the same lettered note.

Diminished is the named quality given to intervals one semitone smaller than both perfect and minor intervals.

I have made bold three sentences to help answer your question. They are:

The unison, fourth, fifth and octave are perfect.

The second, third, sixth and seventh are major.

Diminished is the named quality given to intervals one semitone smaller than both perfect and minor intervals.

The only intervals that can become diminished are PERFECT and MINOR.

Perfect intervals are found within the major scale - they are the Root, fourth and fifth. Think of the I, IV and V chords of a typical blues or rock ‘n’ roll song. Those I, IV and V chords are built on the perfect intervals.

Minor intervals are created by reducing the size of any major interval. This means there exist minor 2nd, minor 3rd, minor 6th and minor 7th intervals (not minor 1st or minor 4th or minor 5th or minor 8th because they are perfect).

Let us look at the major 2nd reducing to minor 2nd - based on your question.

From Root to major 2nd is a distance of two semitones. If that major interval is reduced in size, to become just one semitone, it will then be a minor 2nd. Reducing it in size one further semitone takes it back to zero, back to the Root, to a point where it does not actually exist as an interval.

Root → minor 2nd → major 2nd

diminished 2nd ← minor 2nd ← major 2nd

This hopefully explains why there is no diminished 2nd interval.
For all other perfect and minor intervals, reducing them by one semitone (to make them become diminished) does not lead back to zero (the Root) but to a note that is still at a distance away from zero.
Cheers
Richard