What Makes INTERVALS Sound Consonant or Dissonant?
One of the perks of posting about Music Theory on multiple social media is that I receive the strangest comments and weirdest ideas about music from all over the planet.
Basically, I gather all kinds of "music conspiracy theories" for my amusement... and keep them in the "cabinet of curiosities of Dr. Zillio".
It's not part of my job, strictly, and of course I don't believe any of that... but that's something that entertains me. And occasionally, I find some real bangers! (1)
And even more rarely - but it does happen - I find that while the idea is weird, untenable, and provably wrong, it gets repeated all over the 'net as if it was true.
Do you want an example? There you go:
"Certain combinations of notes (i.e. intervals) sound dissonant or consonant because of the ‘ratio’ between the frequency of the notes."
At this point, more than half of you are thinking: "Er... Actually Tommaso, that's true..."
And I would not blame you, since everybody is repeating this ad nauseam on social media...
But I am telling you that this is most definitely not true. (More than telling, I'll be demonstrating)
See, your perception of how dissonant an interval is depends on several other elements than the frequency ratio.
And - this is the good news - we can use these elements to make your chords and your music more or less dissonant - without changing the notes.
Don’t believe me? Let me prove it to you. In the video below I'm showing you not one, not two... but five different elements that make the same interval more or less dissonant, even if the frequency ration of the notes do not change.
- "Banger": something unusual and impressive. Since I am looking for weird ideas, you can be assured that "banger" is not a compliment in this case...
Want to know more about consonance and dissonance? Then you need to learn more about chords! Check out my Complete Chord Mastery guitar course if you want to vastly improve your knowledge of chords and harmony on the guitar.
Video Transcription
Hello Internet, so nice to see you, let's talk about intervals, and let's talk about dissonant intervals, and let's talk about how to make dissonant intervals more or less dissonant. Now, you may have heard, if you know anything about music theory, you may have heard that some intervals are consonant because the ratio of the frequency is a simple number, and other intervals are dissonant because the ratio of the frequency is not, and so these determine if an interval is consonant or dissonant, that's not true.
Okay, I'm going to eliminate this misconception immediately. Dissonance is not something that happens in physics, okay, dissonance is something that happens in your ear. Dissonance is quite literally an auditive illusion, and I'm going to show this to you right now, okay?
Because we can manipulate dissonance without manipulating too much the frequency, or even without manipulating the frequencies at all, okay? It's a perceptual phenomenon, not a physical phenomenon. Now, that's kind of a boring introduction to show you something incredibly cool, okay?
Because you can take the stinkiest of interval and make it sound good, or you can take the tamest of interval and make it sound progressively bad, okay? To make everything more evident, I am going to use the most dissonant interval that we have available, which is...
If you were thinking the tritone, you are wrong. The tritone is not the most dissonant interval we have, I mean, it is fairly dissonant, don't say no. But the most dissonant interval we have is the minor second.
I mean, this is positively stinky, okay? So, let's do that. It is so stinky that my automatic transcription system can't even imagine having those dissonance at the same time, okay? So, how can we make this interval more consonant or more dissonant?
Well, think about that, right? now I'm playing G sharp or A flat, whatever, and A. Okay, let me actually change and let's play A and B flat. Okay, now if I play those two at the same octave, bad, right?
But if I'm starting to increase the distance between those two octave by octave, okay, so for instance if I play the A here, but the B flat here, this is still dissonant, but less. I play the A here and the B flat here.
This is still dissonance, but even less. And if I play this, you may even start to wonder if this is actually dissonance or not. I mean that's A, A, and B flat. It's dissonant, but it's not as urgent as this.
Okay, so way number one we have two. Change if an interval is perceived by as dissonant or not or at least manipulated dissonance is to increase the distance between the two notes How would you apply that but for instance if you're if you're playing a ninth chord that you can play Let me play an F May play an F sus 2 this way F G C F okay is F and G are together And they sound lovely to me, but some some times you may think this is a bit Dissonant if this is the case just make sure you put the G notes on the higher octave to respect from these It sounds a bit more open and less dissonant and this happens especially if I also have if I also have a A major third which is have to be hard to play on a guitar because I have to play F G and A all at the same time Okay My if I have F A and G at the higher octave That's less dissonant.
Okay, so That's something a practical application of this trick, but that's not the only way to make something more or less dissonant. Okay, another trick is to manipulate the attacks. Okay, let me take those two notes here This is a E flat or D sharp and then E Okay, if I play them together They sound decent if I put them together, but I stagger the attacks meaning They still sound dissonant but it's more acceptable in a sense, okay, it's it's less stinky, okay It's still very dissonant.
Okay, by the way by the end of this video, I'm gonna show you how to make make this one sound incredibly sweet, you will not believe it, okay. But let's get there, step by step. Another way to manipulate the dissonance.
So, sorry, let's come back to this. Stagger the attack. So, if you have a chord that is particularly dissonant, rather than playing it with all the attacks together, so all the notes at the same time, arpeggiated, and it will sound less dissonant.
Next, I can move the whole interval up and down. So, if I play, let me take again the A and B flat, okay. So, if I play the A and B flat down here, it sounds dissonant, because both those frequencies, both those pitches are very, very low.
But if I play the A and the B flat up high here, It's a bit hard to play it cleanly, but... It is still dissonance, I mean, it still kind of stinks, but it's less offensive than this. Okay, this effect, on the range of a guitar, you can hear it, but not so much.
If you were taking a bass to go lower, and maybe some means a violin to go higher, you would notice this even more. If you go higher and lower in the octaves, every dissonance interval played with both notes high up enough becomes consonant, and every consonant interval, if you play it low enough, eventually becomes dissonant.
So, even if I play a minor third, a minor third, let me play like F sharp and A, it's a perfectly consonant interval, it's an imperfectly consonant interval, but it's a consonant interval, but if I play down here, it starts to sound muddy.
If I play this on a bass, okay, it starts to kind of be dissonant too. Okay, so that's another thing, move the notes high or low. If you have a dissonant chord, play the whole thing higher, maybe an octave higher, maybe two octaves higher, okay, and it will sound more consonant.
Next, hear this, that's a half step again, a minor second. If I play this, it's dissonant. If I play this, I lower the volume and play it quieter, it sounds more consonant. If I play it louder, okay, it's fire alarm, okay, it sounds more dissonant.
So, dynamic enters into the equation, okay, again, it's not a physical phenomenon, it's what happens in your ear. Now, all those are, so again, if you want something more dissonant, play louder, if you want something more consonant, play it quieter, okay.
So, You can combine all those, okay? Now, attention, because the next trick is... You take the dissonant interval. And you don't play it just as an interval, okay? So I'm gonna give you two examples.
The first one is this. I'm taking E and F. I could play E and F here. But I'm expanding them to an octave, to a minor ninth. Okay? And now, those two are dissonant, clearly, okay? But to make it more acceptable to our ear to reduce the perceived dissonance, I'm playing other notes in between, then support those.
If I just play these... And if I play these... This sounds less dissonant. It's kinda... The other notes are justifying, okay, the dissonance between the extreme notes, okay, because this G -sharp, which the automatic transcription system writes as A -flat is the G -sharp, okay, is consonant with the E, and this D note is consonant with this F, so they kind of support, okay, those two notes, and so you hear the clash less, okay.
Now here it is. I'm taking this D sharp E or E flat E together, and I'm playing this under there. That's how it sounds, just the dissonance, and that's how it works with supporting notes. That's B, F sharp, C sharp, D sharp, E, okay, so it's a B major triad, okay, in which I add the 9 and the 4, okay, you can call it 9 11 if you want, okay, or just 11 with no 7, whatever, as usually, you can invent all the names you want for this, okay.
The point is, hear how those two notes that played by themselves are very sour, okay, when I play the supporting notes, the dissonance becomes sweet, okay, and we do some alchemy to all this chord, okay, and we transmute all the sourness of the chord into pure sweetness, okay.
I could have done this also with just a B major triad. But the extra 9. It's even better, okay? So, okay, so this also manipulates the dissonance of the chord. Those two pitches did not change, but the context of the pitches changed in your mind, because I'm playing other notes, and your brain doesn't hear those as dissonant anymore.
They hear your ear hears this as a spice on the chord, not as a clash between two notes, okay? So, all these should show you that it's more of a psychological perceptual phenomenon than a physical phenomenon.
But what is interesting for us as musicians is that you can take even the stinkier of the intervals like this, and by changing. How distant are the two notes? How high or low are the two notes? If you play the attacks together or separate, if you play at a high dynamic or low dynamic, and if you play supporting notes and which supporting note, you can totally change the feeling of that interval and make it more or less consonant to suit your music.
And that's a simple example of how music theory helps you doing something that people consider magic, because it's still the same two notes, okay? Now, if you want to know way, way, way more about chords, harmony, and how to use them in your song, I recommend you take a look at my course Complete Chord Mastery, okay?
It's a video course and it's complete, like the name says, it's complete. It teaches you everything you need to know about chords and harmony on guitar, how to find the chords, how to play the chords, how to create chord progression.
It's a theory course and it's a practical course, okay? I'm not just giving you everything in theory, I'm showing you pattern diagrams, ways to find the chords around, ways to combine those chords, way to play those chords, and way to actually make real guitar parts that sounds in different styles using those chords, okay?
So, fairly complete, I'd say, okay? So, have a look at Complete Chord Mastery. This is Tommaso Zillio for musictheoryforguitar.com and until next time, enjoy!