Triad Chord Theory

Learn the four types of triads and how to apply their formula to the Major Scale.

View the full lesson at Triad Chord Theory | JustinGuitar

Very nice and interesting course. Thank you Justin!

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I loved the augmented mystery expression hahahaha, that was CLASS, priceless & timeless!

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It’s soo cool seeing this stuff all start to come together, loving the theory course! :+1: :clap:

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Feeling the same way Fncanuk. It’s exciting to learn what we are and seeing previously mysterious terms start to make sense.


Is there an understandable reason, why no “double augmented” triad exists? If I look at the four triads, I automatically think, “why is there no triad with 1 / 3# / 5#?”

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Hi there,

Augmented triads already have two major 3rd intervals in them, so sharpening the first major 3rd by a semitone would raise it to a 4th, and the second one would become a minor 3rd.

That would make it a sus4 diminished triad, if that naming exists.


Ok, so I’m trying to work out the triads for all the major notes in the major scale. I’ve gotten to B and I’ve run into a hiccup. For the Augmented Triad, is it B, D, F## (or F*…or whatever the proper notation is) or would you say B,D,G?


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Hey Adam,

B Aug would be written B D#, F##

Cheers, Shane

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Hello @JanWartenberg and welcome to the community.
See if this helps.

If you look at the major scale formula, with C major below as an example, you can see that some notes are two semitones apart (a whole tone) and some just one semitone apart.
Between the 2nd and 3rd scale degrees there is a two semitone distance. Thus, the 3rd can be lowered (flattened) by a semitone and it does not encroach on the note below.
Between the 3rd and 4th scale degree is just one semitone. If the 3rd was raised (sharpened) it would occupy the same space as the note above it, the 4th. You could forcibly call it a #3 and view it as an enharmonic equivalent to the 4th scale degree. But that is not what happens. Instead, if the 4th scale degree is played within a chord because the 3rd has been raised, we call it the 4th and the chord becomes a sus4.
No such limitation applies to the 5th scale degree as there are two semitones either side of it so it can be flattened or sharpened.

Plus, as @Jozsef says, it is also the internal intervals that make up any chord. An augmented triad must contain two major 3rd intervals by definition.
I hope that helps.

Cheers :smiley:

| Richard_close2u | JustinGuitar Official Guide, Approved Teacher & Moderator

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Do you mean all notes in the chromatic scale? You are exploring triads for all 12 notes?

The D note should be D#, not D natural.

For augmented triads, start with the major triad and raise the 5th scale degree note by one semitone BUT keep the alphabetical letter name. You cannot call it by the next alphabetical letter name even if it has that as an enharmonic equivalent.

B major: 1, 3, 5 → B, D#, F#

B augmented: 1, 3, #5 → B, D#, F##

The double sharp symbol resembles a bold letter x if you see that written.