Major vs minor scales: what actually differs

A major scale and a minor scale both have seven notes, but they arrange their whole steps and half steps differently. The major scale follows whole, whole, half, whole, whole, whole, half; the natural minor follows whole, half, whole, whole, half, whole, whole. The decisive difference is the third note: four semitones above the root in major, three in minor. The scale finder spells both in any key and plays them so you can hear the change.

The step patterns

A whole step (W) is two semitones and a half step (H) is one. Starting on C and using only white keys gives C major: C, D, E, F, G, A, B, with half steps between E and F and between B and C. Apply the same pattern, W W H W W W H, from any other note and you get that major scale, adding sharps or flats where needed. G major needs one sharp (G, A, B, C, D, E, F♯) and F major one flat (F, G, A, B♭, C, D, E). Each letter appears once, which is why F major contains B♭ and not A♯.

The natural minor pattern is W H W W H W W. From A it uses only white keys: A, B, C, D, E, F, G. From C it gives C, D, E♭, F, G, A♭, B♭. Compared with C major, three notes are lowered: the 3rd, 6th and 7th.

Why they sound different

The third sets the mood of the scale and of the chord built on its first note. A major third (four semitones) sounds bright and settled; a minor third (three) sounds darker. The lowered sixth and seventh add to that colour in minor. Calling major happy and minor sad is a useful first description, but it is learned as much as heard: plenty of cheerful dance music is in minor, and slow major ballads can be melancholy. Tempo, rhythm and lyrics shape the mood as much as the scale does.

Relative and parallel keys

Every major key shares its notes with one minor key, its relative minor, which starts on the sixth note of the major scale, three semitones below the root. C major and A minor share the same seven notes and the same key signature with no sharps or flats; G major and E minor share one sharp; F major and D minor share one flat. The circle of fifths shows all twelve pairs, and The circle of fifths explained: keys, signatures and chords explains the pattern.

Parallel keys share a root instead: C major and C minor start on the same note but differ in three notes. Switching between parallel keys is a classic way to change the mood of a song while keeping the same home note.

Three kinds of minor

Minor comes in three common forms:

• Natural minor: A, B, C, D, E, F, G. The plain pattern described above.
• Harmonic minor: A, B, C, D, E, F, G♯. The 7th is raised so that the chord on the fifth note becomes major (E, G♯, B), which pulls strongly back to A minor. The gap from F to G♯ gives it a distinctive exotic sound.
• Melodic minor: A, B, C, D, E, F♯, G♯ going up. Both the 6th and 7th are raised to smooth that gap. In classical practice the descending form usually returns to the natural minor; in jazz the raised form is used both ways.

The scale finder shows the ascending melodic minor, and lists all three alongside the modes, which Musical modes explained: the seven modes and how to use them covers in depth.

Working out the key of a song

Because relative keys share notes, the notes alone cannot always tell C major from A minor. Listen for the home note, the one the melody and chords resolve to at the end of phrases. If it is A and the opening and closing chords are A minor, the song is in A minor. A G♯ appearing in an otherwise white-note song is a strong hint of A minor, from the harmonic form. The scale finder can also work in reverse: click the notes you hear in a melody or riff and it lists every major, minor, pentatonic and blues scale that contains them all. Then test the strongest candidates with the chord progression generator, which builds the main chords of any major or minor key.