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understanding intervals in any key - major and minor triads, sevenths etc...


Local Dive Bar Favorite
Nov 11, 2019
Hello there, I really hope it will help some of you who are not familiar with this… it is a little brain exercise to figure out intervals. I had a very hard time following all those youtube lessons and basically every Rick Beato video, about theory, scales, chords and intervals, just because I was not able to do the math in my head. Knowing the 1 – 3 – 5 in any key, the chord tones etc… so I sat down with pen and paper, writing down the intervals in every possible way on fretboard and trying to figure out ways to know it instantly without guitar, without anything, just saying a note and come up with answers what is the major second? Minor second, fifths, sevenths etc… and how to figure it out fast without counting up and down the scale… and of course being able to play it on the guitar and use it in lead. so here is how I do it now… I hope it makes sense and that it will help.

So I want to know (almost) instantly the notes of any major or minor triad…

First thing to know is the formula 1 – 3 – 5 . It is the first, the third and the fifth note in the major scale. When it comes to major triads, major chords, it is always 1 – 3 – 5, you go to sleep it’s onethreefive, you get up in the middle of the night to pee it’s one.three.five… even when you eat your breakfast or walk your dog, it’s one. three. five. when you watch tv, it's One.Three.Five. It’s not One.Tree.Hill. It’s ONE.THREE.FIVE


The first is easy. It is the root note that you picked, let’s say A. This is the 1. The 1 is the root note.:


Now let’s find the major third of A. That is the 3.
It involves a bit of counting, but it gets easier and faster the more you do it.

One way you just go up to the third letter, let's say F is the root, go up F G A... A is the major third.
but if there are no sharps or flats between, then you sharpen the third note.. There are no notes between E - F and B - C. These are the only places. So if you the root is A, go up A B C, but because between B and C there is no note, sharpen the C, becomes C#, as the major third of A.

Take G as root, go up G A B... B is the major third.
Take B as root, go up B C D...again we have B and C here, there is no note between them, so sharpen the D, becomes D# as the major third of B.
Now E is the root, E F G... between E and F there is no note, so sharpen the G, becomes G#.
When D is the root, D E F.... between E and F there is no note, so sharpen the F, becomes F#.

Another way:

The first three notes of the major scale have 1 empty fret between them, so just leave out every second fret, and you can get to the major third in no time in your head… just imagine this picture that I stole from guitar pro 7:


So which is the major third?

A ? no, it is the Root
A# -is not in the scale
B ? no, it is major second
C – is not in the scale
C# - yeayeayea it is the major third. Command over. Semicolon.

It does not matter, which note you start on. In key of D, the root is D, the major third is F#.


D – is the Root
D# - is not in the scale
E – is the major second
F – is not in the scale
F# - is the major third

So just do this in your head next time on the bus, at work, before sleeping, under the shower, or while your drunk uncles are debating politics and solving all the major problems of the planet at a family dinner:

Pick a note, for example G.
G is the Root.
G# - Skip this note it is not in the scale
A is the major second.
A# - Skip this note it is not in the scale
B is the major third

Done, awesome, congrats, now be proud at yourself, then pick another note, and repeat until you can do this as fast as... I don’t know, very fast.
So now you know the 1 and the 3.

Now the fifth! Do we count up from the root? NO. Do we count down from the root? NO. Too far. Too much work, brains don’t like that, brains hurt then. Brains like easy patterns. Here is an easy pattern:

What is the fifth in A? In standard tuning what is the string above your A string? E. The fifth of A is E.
A – B – C# - D – E – F# - G# - A


What is the fifth in E? In standard tuning the string above the E is B. The fifth of E is B.
– F# - G# - A – B – C# - D# - E

What is the fifth in G? In standard tuning the string above the G is D. The fifth of G is D.
G – A – B – C – D – E – F# - G

What is the fifth of D? In standard tuning the string above the D is A. The fifth of D is A.
D – E – F# - G – A – B – C# - D

Now there is an exception, but easy to remember:

The string above the B string is the G string, but the fifth of B is not the G, it is one fret below, it is F#. So the fifth of B is F#... and if we go 1 fret up to C the fifth of C is G. Just remember this another beautiful picture.


So only the fifth of F left, which is a C. As a reference can be an F5 chord, or above the F note there is a C (except on G string).

These are all the fifths… if you sharpen a root, the fifth sharpens too: The fifth of G is D. The fifth of G# is D#

and if you flatten a root, the root goes flat too. The fifth of G is D. The fifth of Gb is Db

Now all the 1 – 3 – 5 can be figured out easily and fast with a little bit of mental exercise. Of course, like everything, it needs to be practiced a bit, but you can do this anytime anywhere… and you should! Because if someone runs up to you on the street and say he/she will kill you if you don’t tell immediately the onethreefive of the B, now you will be able to tell it and it can save your life. De nada

… and the major Seventh! It is the same like 1 – 3 – 5 , but add a 7 to that. 1 – 3 – 5 – 7 one.three.five.seven.

Where is the major seventh? 1 fret below the root. Always. Forever.

The major seventh of E is D#.

The major seventh of B is A#.

The major seventh of C is B.

The same applies to minor triads, minor chords… just flatten the 3 and 7, the fifth is the same.

1 – b3 – 5

1 – b3 – 5 – b7

The b3 of D is F. Again, remember this nice small pattern.


and the b7 is always 2 frets below the root.

The b7 of D is C.

The b7 of C is Bb.


Again, I really hope I managed to write this down clearly and that it will help.

Happy Holidays!
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