A-flat major

A-flat major is a major scale based on A♭, with the pitches A♭, B♭, C, D♭, E♭, F, and G. Its key signature has four flats.

The A-flat major scale is:

$\header { tagline = ##f } scale = elative a { \key as \major \omit Score.TimeSignature as'^"A♭ natural major scale" bes c des es f g as g f es des c bes as2 \clef F \key as \major } \score { { << \cadenzaOn \scale \context NoteNames \scale >> } \layout { } \midi { } }$

The A-flat harmonic major and melodic major scales are

$\header { tagline = ##f } scale = elative a { \key as \major \omit Score.TimeSignature as'^"A♭ harmonic major scale" bes c des es fes g as g fes! es des c bes as2 \clef F \key as \major } \score { { << \cadenzaOn \scale \context NoteNames \scale >> } \layout { } \midi { } }$

$\header { tagline = ##f } scale = elative a { \key as \major \omit Score.TimeSignature as'^"A♭ melodic major scale " bes c des es f g as ges fes es des c bes as2 \clef F \key as \major } \score { { << \cadenzaOn \scale \context NoteNames \scale >> } \layout { } \midi { } }$

Its relative minor is F minor. Its parallel minor, A-flat minor, would require seven flats and is usually written as the enharmonic key of G-sharp minor instead, with five sharps.

In tuning systems where the number of notes per octave is not a multiple of 12, notes such as G♯ and A♭ are not enharmonically equivalent, nor are the corresponding key signatures. These tunings can produce keys with no analogue in 12-tone equal temperament, possibly requiring double sharps, double flats, or microtonal alterations in key signatures.