How Musical Keys Are Built And Not Break Your Brain In 2 Practical Steps

Musical keys and how they are constructed is the basic starting point for understanding music theory and it is the part that most people get stuck on.

But it does not have to be that way.

The way that a normal major scale is built up is pretty straightforward because it always follows one specific formula.

What is confusing about it is that when you change the root note, some note names change a bit, some don’t.

Some notes get a # symbol or b, for example F# or a Bb. (Say: F sharp, B flat)

And another confusing thing is that the first scale we ever learn, C major, has this formula already built in so that the interval (the tonal distance) between some notes is not consistent.

But there is a method to the madness.

1. The Major Key Formula

Here are the notes of the C major scale from C to the next C one octave higher:

C D E F G A B C.

Now we have Full Tone Steps (2 Frets on the guitar) between EVERY NOTE EXCEPT between E and F, AND B and C.

Those are half steps (or 1 fret on the guitar).

That means you can imagine the C major scale “created” as fitting into the major key formula, if you will.

The formula goes like this:

Root note (C) -> Full step (D), full step (E), half step (F), full step (G), full step (A), full step (B), half step (C) -> Root note.

This formula is always consistent, regardless of which note you determine as the new root note.

Let’s for example take the key of G:

Root note (G) -> Full step (A), full step (B), half step (C), full step (D), full step (E), FULL STEP (F#, NOT F, because between E and F is just a half step, so we have to raise the F by a half step by adding the # symbol), half step (G) -> Root note (G).

Let us do ONE more in major before I leave it to you to figure out the rest and show you how to practice this in a more fun way that also helps your understanding.

Key of F:

Root note (F) -> Full step (G), full step (A), HALF STEP (Bb, not A#, because we can use every letter only once and we have to lower the B by adding a b sign to it), full step (C), full step (D), full step (E), half step (F) -> Root note.

So far all we looked at were MAJOR keys, but a lot of songs are also in MINOR keys, but the concept is the same: You have a key formula and you apply it to a root note and get the other notes.

What you will then find is that a minor key can have ALL notes in common as another major key.

We call that relative keys.

2. The Minor Key Formula

Example: A minor.

The Minor key formula goes like this:

Root note -> Full step, half step, full step, full step, full step, half step, full step, full step -> Root note.

With A in the root:

Root note (A) -> Full step (B), half step (C), full step (D), full step (E), half step (F), full step (G), full step (A) -> Root note.

You see that A minor has all notes in common with C major.

Try the same now with E minor and D minor.

Here is how you can practice to help your understanding of musical keys and learn the formula by doing

Below I show you how you play a C major scale with a certain pattern.

Learning it in this way is important for later when you want to start playing guitar solos.

Use your index, middle and pinky finger, NOT the ring finger.

I explain why in this article about how to play fast.

The most important part is to learn how the scale sounds and associate it with this shape.

When you have played it correctly a few times, move this shape to other frets and play it in different keys.

When you move it around, make sure you first give yourself clarity what the first note, the root note, is.

For example: If you move it to the third fret, that is a G note, so you are now playing the G major scale.

Here is the shape for the A minor scale:

This shape should be played with the index, RING and pinky finger.

Same as before:

Get used to playing this shape, then move it to other places on the fretboard and get clear in which key you are in = what is the starting note.

For example: 12th fret, E.

If you start the scale from there, you’re playing the E minor scale.

Now have fun figuring out the rest!

The more you do it, the better you will understand it.

Don’t focus too much on intellectually understanding.

And if you want more customized-to-you help and get your playing really on the fast track:


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