interval quality question

[cryophonik]

C Fb Ab Db: the dissonance is the minor 9th C-Db; they were responding to you saying you keep on with the major third in isolation it's perceived as dissonant, only to provide a case subjectively/contextually where it would be perceived *differently* than a major third's part *in a major triad*.

Agreed. The dissonance isn't necessitated by the diminished fourth, but it's one example where a chord would actually have the C-Fb interval the OP is asking about. Again, without some sort of harmonic context, there's really no other way to differentiate consonance and dissonance between a major third and diminished fourth.

[jancivil]

I don't recall anything specific about the quality of a dim 4 per se. I've done massive amounts of part-writing in the late chromatic style, it felt like I was majoring in it, and any point like that served context. Augmented fifth in an augmented triad has a certain amount going on physically owing to _two_ major thirds at once (more going on than a major triad) but I'm not sure the whole idea of its dissonance isn't conditioning and expectation. In itself it's not diff than minor 6. Once upon a time that was considered a dissonance, just as was a major third.

- - -

as the ^7, sometimes in a line a naked ^7 can be pretty strident.

I favor that minor/major chord a lot, like it's dark chocolate

[shugs]

Yes, I am being taught that all intervals are either consonant or dissonant and within consonant are further classified as perfect or imperfect. No ifs, ands, or buts, or exceptions, or caveats. Specifically, no subjective qualities are mentioned, like "it sounds bad or sounds good" So apparently how an interval sounds may be pleasing or may need resolved or may suck, but these terms have nothing to do with whether the interval is textbook dissonant or not. AT least that is my take-away

[cryophonik]

I favor that minor/major chord a lot, like it's dark chocolate

It sounded quite horrid when I played it on a pad sound on my synth earlier, but on a piano...

[jancivil]

"I am being taught that all intervals are either consonant or dissonant and within consonant are further classified as perfect or imperfect."
that's messed up. That's like being taught in maybe the late medieval era, by puritanical whackjobs.

There are no rules except for style-bound convention or context.

[jancivil]

"horrid when I played it on a pad sound"
sure, the harmonics generated are absolutely part of any conception of dissonance or desirability.
For me, though, 'horrid', 'harsh' is as good as anything, because we get into opinion, opinion with a lot of baggage, with "dissonance" right away.

[jancivil]

"perfect or imperfect" - this old sort of religious idea remains with us in the terminology. Perfect octaves, fourths, fifths.
statements like 'the major third is an imperfect consonance' should be deprecated by the 21st century except as commentary or reference to an historical point. The major third was considered a dissonance by the Roman Catholic Church in that expression during its medieval period, people talking seriously like that today is weird.

But P4 vs A4 or this rather less common d4 is: Perfect to augmented or diminished; major to minor to diminished, or in the other direction minor to major to augmented. Diminished 2nd/augmented 7th won't be seen so frequently.

IE/EG: Augmented sixth F to D# is a spelling with a meaning, owing to a certain function in a certain style; there is no point in talking about it in the abstract, its entire identity stems from usage.
So characterize it as dissonant, no es problemas... what does it do?

Music to me seems all about tension and release, definitions should serve music. What I'm saying about being taught that, in that color, is better said as 'that's dogmatic', no good/don't work.

[fmr]

Is it possible that C to F flat is not dissonant?....I have been taught that ALL diminished pairs are dissonant, but maybe that is not true if they are enharmonic to a consonant pair ?

in 12 tone equal temperament ALL diminished fourths sound the same as major thirds, no matter what notes you have. A diminished fourth is an artificial interval that exists for a matter of tonal and scale coherence (you can't have two C's in a scale, so if you already have C# the note below is B#, which the leading tone).

Consonance and dissonance are completely different concepts. Just out of curiosity - who told you diminished fourths are dissonant, anyway? Aren't you confusing them with augmented fourths, by any chance?

[shugs]

all augmented and diminished intervals are defined as dissonant.

We are not being taught that this is the way to write or appreciate music. We are being taught that this is the classical way of formalizing it. Just as when I start learning counterpoint theory next year, we will be taught what the 'rules' are first, but with full realization that there are no rules in modern day.

I had a little argument with my guitar teacher a few weeks ago. He has me jamming using the scale (any Key) to backing tracks. But this is like me telling someone to sit at a piano and as long as you only play the white keys, what will come out will sound good. If there are some rules to follow/learn first, it makes the process of progressing come quicker

I think one needs to start with some structure and definitions and capitalize on what others have studied before you. Without formality, communication becomes difficult and learning becomes slower than it needs to be,

That's my thinking, at any rate

[shugs]

We are not being taught that one is better than the other. We are taught that with Perfect fifths, that the actual sound waves behave somehow differently than any other interval...maybe they have similar periodic frequencies (?)

[fmr]

all augmented and diminished intervals are defined as dissonant.

No they are not.

We are not being taught that this is the way to write or appreciate music. We are being taught that this is the classical way of formalizing it. Just as when I start learning counterpoint theory next year, we will be taught what the 'rules' are first, but with full realization that there are no rules in modern day.

Again, I don't agree with that. I don't even teach counterpoint as in the Fux treaty. I think that's unnecessary.

I had a little argument with my guitar teacher a few weeks ago. He has me jamming using the scale (any Key) to backing tracks. But this is like me telling someone to sit at a piano and as long as you only play the white keys, what will come out will sound good. If there are some rules to follow/learn first, it makes the process of progressing come quicker

I think one needs to start with some structure and definitions and capitalize on what others have studied before you. Without formality, communication becomes difficult and learning becomes slower than it needs to be,

That's my thinking, at any rate

Well, you are in the wrong business, if you seek some kind of "safety net" to work with in the first place.

Sure you need "some structure and definitions and capitalize on what others have studied before you". That's why I say: Study the classics, sure they are a great school. Learn how they did things and, most important, WHY they did what they did. Start by analyzing very simple pieces, and slowly go further.

But bear in mind that the only rule in music is that THERE ARE NO RULES. For example, if you are studying counterpoint as a path to an end, you will be frustrated to know that even Bach didn't follow all the rules all the time. Why? Because to him, as it should be to anyone composing music, music comes first. Music is what matters.

You should start by writing melodies alone, but melodies that are able to survive by themselves, without any kind pf accompaniment. And you should learn the music syntax of phrase or sentence, period, forms, cadences, etc. Forget all that rubbish about consonance and dissonance. Like jancivil stated, in music there's tension and relaxation. Dissonance is anything that creates tension - consonance is anything that brings relaxation. And that's it. An interval is just the distance between two written notes.

[jancivil]

well, some of that is probably a "classical" way to classify things, but "all x or y are dissonant" takes the name for something over the thing itself.
An augmented second is a minor third except in spelling, which has a meaning belonging to its use case. So you cannot consider the word augmented here to mean a difference per se, the interval is three semitones wide. We could get into detail in different intonations as to how wide those semitones are, but that's what it is: the statement 'a minor third is dissonant' is the same statement. Ok, but this is not useful, it's just commentary, and that's very stick-in-the-mud.

[shugs]

Well, on the guitar exercise, when the backing track chord shifts, some notes will sound better than others; All notes in the scale are not created equal is the point I was trying to make with him .

Most of your comments I agree with. I'll go look back, but I am pretty sure my text has augmented ingervals are dissonant

[jancivil]

In any case, I want you to grasp that names for a thing over the thing itself is fundamentally a failed logic.
3 semitones, is that dissonant? I don't even have an opinion on that, but augmented = dissonant strictly through the term augmented is no good.

[BertKoor]

I was thinking it had something to do with the actual frequency and amplitude of the sound waves, and how the two notes mesh together

Amplitudes: naah.

We are taught that with Perfect fifths, that the actual sound waves behave somehow differently than any other interval...maybe they have similar periodic frequencies (?)

Frequencies: yes!

Let's explore frequencies for a while, and at the end I'll get back to the core problem at hand.

So you play guitar. Did you ever notice how strings sound different depending on where you strum them? It sounds mellow when you strum them halfway and more nasal when strummed close to the bridge. Strings don't only vibrate at their base frequency, but also at the exact multiples of that: harmonic frequencies. Rest a finger gently at the 5th or 7th or 12th fret on the string, you get only that harmonic tone and not the base tone. The same can be done with flutes by overblowing.

The lowest note on guitar (let's refer to that as E0) has a frequency of 82.4069 Hz. Let's make the math a bit easier and round it off to 82.5Hz which is only 2 cents off. How do I know that? See the link to MusicCalc in my signature.

The first harmonic is twice the frequency: 165Hz, that's one octave higher E1. You get this tone at the 12th fret.
Three times 82.5 = 247.5 Hz which is B1. Not exactly though, it's 2 cents out of tune in Equal Temperament (ET) tuning. One third of the strings length happens to be at the 7th fret.
Next harmonic is at 4x 82.5 = 330Hz and that's E2. A quarter of the strings length is at the 5th fret.
Next one at 5x 82.5 = 412.5 Hz is G#2. It is 14 cents flat for a major third in ET, but close enough.
Next one at 6x 82.5 = 495 Hz which is B2.
Next one at 7x 82.5 = 577.5 Hz which is D3. Minor seventh interval with E2 and 31 cents flat for ET.
Then 8x 82.5 = 660 Hz and you're at E3. Beyond that it all becomes a bit messy.

Side note: we can do the same thing for the A string: 1 x 110 = 110 Hz = A0, 2 x 110 = 220 Hz = A1, 3 x 110 = 330 Hz = E2. We've seen that frequency before. You can use this principle to tune the guitar.

From E to B is the perfect fifth interval, and this also is the strongest harmonic frequency of a string. No wonder it's at the base of almost every chord. It's so strong that you can omit it in playing, it's presence is almost assumed/inferred by the listener. Or vice versa: play only root + fifth + octave. That's the Power Chord which is neither major nor minor.

Speaking of major & minor, that's the third interval from the tonic: major third or minor third. Chords in contemporary music is built (in general) by stacking thirds intervals.

So intervals that are almost guaranteed to sound nice (consonant) are:
- the perfect fifth
- the perfect fourth, being inverse of perfect fifth: 5th + 4th = one octave
- major third or minor third depending on context which is the current scale amongst other things.

When playing melodies over a chord, you might notice how melody notes are at ease when they are on one of the notes of the chord but there is an urge to move when they are not. That is tension - as in an elastic band - and there is a certain need to release that tension. I can write some more on tension if you like.

Now to address the problem at hand: if the third note of the current scale is the major third, then that's that. In that scale there is no such thing as a diminished fourth interval. Imho that can only occur when the third note of the scale is a minor third.