The major scale — Music Theory

The major scale is the reference everything in Western music compares against. When we say a chord is “minor,” we mean minor relative to the major scale. When we say a key is “dark” or “bright,” we’re describing how far it sits from the major. So this is the one scale to truly understand.

A major scale has seven notes. The eighth — the octave — repeats the first. Between those eight notes, the pattern of half steps and whole steps is always the same:

The major scale formula

W – W – H – W – W – W – H

That’s it. Whole, whole, half, whole, whole, whole, half. If you start on any note and apply that pattern of steps going up, you’ve built a major scale.

Building C major

Let’s start on C Do and apply the formula:

Step	From → To	Distance
1	C Do → D Re	whole
2	D Re → E Mi	whole
3	E Mi → F Fa	half
4	F Fa → G Sol	whole
5	G Sol → A La	whole
6	A La → B Si	whole
7	B Si → C Do	half

The result:

C major scale

Click the highlighted keys in order, left to right. You’re playing C Do major. It uses only white keys — no black keys. That’s the reason every beginner theory book starts here: C Do major is the only major scale that fits entirely on the white keys of a piano. It’s the simplest visual case for the formula.

Now build G major

Start on G Sol and apply the same formula:

Step	From → To	Distance	Note
1	G Sol → A La	whole	✓
2	A La → B Si	whole	✓
3	B Si → C Do	half	✓
4	C Do → D Re	whole	✓
5	D Re → E Mi	whole	✓
6	E Mi → F# Fa#	whole	⚠️
7	F# Fa# → G Sol	half	✓

Look at step 6. E Mi to F Fa is only a half step (remember from chapter 1.5 — there’s no black key between them). But the formula requires a whole step at that position. So we have to raise the F Fa by a half step — to F# Fa# — to satisfy the pattern.

G major scale

Same pattern, every key

Try D Re major in your head using the formula:

D – E – F♯ – G – A – B – C♯ – D

Two sharps. The formula forces them. And here’s A La major:

A – B – C♯ – D – E – F♯ – G♯ – A

Three sharps. Same formula, different starting note, different consequences.

This is the whole game. Every major scale you’ll ever encounter is just W–W–H–W–W–W–H applied to a different starting note.

Every letter appears exactly once

Notice something in the scales above: G Sol major uses F# Fa# (not G♭). D Re major uses C# Do# (not D♭). A La major uses G# Sol# (not A♭).

This isn’t an accident. A major scale always contains each of the seven letters exactly once. This is why we have enharmonic equivalents — the choice between F# Fa# and G♭ depends on which letter is missing from the scale. In G Sol major, the letter F is already in use, so the sharp note is named F# Fa# , not G♭.

Recap

The major scale is built from a fixed pattern of steps: W – W – H – W – W – W – H.
Apply that formula starting on any note and you get the major scale in that key.
The formula naturally produces sharps (or flats) when the starting note requires them — they aren’t memorization, they’re consequences.
A major scale always uses each letter A–G exactly once. This rule decides whether a note is named sharp or flat.