Clarification on intervals

There are several ways to calculate the width of an interval; the two most widely accepted methods are:

The one I like least is counting the number of semitones: if there are 3, then it is a minor third. For a beginner, this is immediate but has its limits, especially for wider intervals.

The one I like most is referring to the major scale, although this requires knowledge of other concepts. But let's see.

In a dyad (2 sounds), the lowest sound can be seen as the first note of the scale (major in this specific case); therefore, in the case of "do mi", the reference scale would be C major, and since there are no accidentals, the interval will certainly be major.

In the case of "mi sol", however, the reference scale would be E major (4 #, fa# do# sol# re#); thus, if it were a major third, it would have to be "mi sol#". Since the sol is lowered by one semitone, it is a minor third, and indeed in E minor, the sol is natural.

With time, as you master keys, it will be a moment's work to reduce major and minor thirds, sixths, and sevenths. Clearly, there are also other cases: perfect interval, augmented, diminished, doubly augmented, doubly diminished.

Buffalo wrote:

reposted with a different formatting, because I tried to Edit, but it tells me that I do not have the permissions.

thanks Rotore, you were very clear.

At least for the moment, I thought of using this method:

For example, measuring the interval G# - F.

1) I consider the major scale of the starting note, i.e., G# which is this:

G# - A# - B# - C# - D# - E# - F## - G#

1st 2nd 3rd 4th 5th 6th 7th 8th

2) I look for the arrival note within the scale:

The arrival note F is present at the Seventh degree with 2 sharps

3) By subtracting the two sharps, step from MAJOR -> Minor -> Diminished.

Therefore, the interval G# - F is a Diminished Seventh.

Doing this, it becomes clear that the interval E - G (which I didn't know how to measure) will be a Minor Third because:

1) I consider the major scale of the starting note, i.e., E which is this:

E - F# - G# - A - B - C# - D# - E

1st 2nd 3rd 4th 5th 6th 7th 8th

2) I look for the arrival note within the scale:

The arrival note G is present at the Third degree with 1 sharp

3) By subtracting the sharp, step from MAJOR to Minor.

Excellent Buffalo

Buffalo wrote:

At least for the moment I have thought about using this method:

Practically it is Rotore's second option

Buffalo wrote:

Do-MI is a major third and MI-SOL should also be one.

and who says so? if both were major thirds, you would have an augmented triad, not a major triad

I would simply like to say my piece. The perfect major chord is called such because it is not a "construction," but exists in nature. In fact, let us remember that the first harmonics of any note, for example C, are precisely E and G. That is not enough: in the physical-harmonic phenomenon, the fundamental is tripled. The fifth (G) appears twice, weakly, and the E only once, but significantly. By reproducing these first harmonics simultaneously, we obtain exactly the "perfect" major chord. Around these important notes, the scale model develops. I like to tell a little fairy tale to children, in which I compare the tonic (Fundamental) to a King, the third E (modal) to the Queen, and the Dominant (G) to the Prime Minister. Even the Leading Tone (B, the seventh degree of the scale) is important and, throughout history, becomes the King's mistress. Aside from this slightly "immoral" surprise, the other notes of the scale are "undersecretaries"... or simple subjects (supertonic; subdominant; superdominant). Therefore, the intervals of the perfect major chord cannot be questioned. They exist as they are. It is no coincidence that the rules of tonal harmony, which teach us and require us to be able to double the fundamental, forbid us from doubling the third (the modal) and leave us free to omit the fifth (dominant). In fact, this respects the nature of the first six harmonics: the reinforced fundamental, the third appears only once, and the fifth does not appear among the very first harmonics. In short, everything according to nature.

It is not so for the minor chord, which is obtained by lowering the Queen's "mood," which, by becoming sadder, generates and invents a different emotional model. In the "harmonic" scenario, even the leading "mistress" plays an important role... but I do not want to go on too long.

After these crude examples, which will scandalize my fellow Composers, I hope I have not created confusion. Long live the perfect major chord that I prefer and which for now still corresponds to my "mood." I hope at least to have entertained you.

Happy Music

pianoexpert, I thank you because you certainly entertained me, but not just that.

It's exactly what I am looking for around... that is, something that explains the role of each degree well. Aside from the technical meaning, I am referring specifically to the flavor of each degree.

Not only do the scale degrees have a different flavor, but the keys themselves do as well. Composing in G minor is not equivalent to choosing C minor. Unfortunately, we pianists, with equal temperament, are used to hearing the same ratios. But let us think that the natural scale is richer and all to be explored. More than me, a composer can exemplify all this. I will limit myself to saying that we know well how often Mozart uses the key of G minor and Beethoven uses that of C minor. And so? How many flavors in the pantry of Music!!!!