A♭ (musical note)

{ \new Staff \with{ \magnifyStaff #3/2 } << \time 2/1 \override Score.TimeSignature #'stencil = ##f { \clef bass aes1_A-flat \clef treble aes'_A-flat } >> }

A (A-flat; also called la bémol) is the ninth semitone of the solfège.

It lies a diatonic semitone above G and a chromatic semitone below A, thus being enharmonic to G, even though in some musical tunings, A will have a different sounding pitch than G.

When calculated in equal temperament with a reference of A above middle C as 440 Hz, the frequency of the A above middle C (or A4) is approximately 415.305 Hz. See pitch (music) for a discussion of historical variations in frequency.

The notes A and G are the only notes to have only one enharmonic, since they cannot be reached in any other way by a single or double sharp or a single or double flat from any of the seven white notes.

Designation by octaveEdit

Scientific designation Helmholtz designation Octave name Frequency (Hz)
A−1 A͵͵͵ or ͵͵͵A or AAAA Octocontra 12.978
A0 A͵͵ or ͵͵A or AAA Subcontra 25.957
A1 A͵ or ͵A or AA Contra 51.913
A2 A Great 103.826
A3 a Small 207.652
A4 a One-lined 415.305
A5 a′′ Two-lined 830.609
A6 a′′′ Three-lined 1661.219
A7 a′′′′ Four-lined 3322.438
A8 a′′′′′ Five-lined 6644.875
A9 a′′′′′′ Six-lined 13289.75
A10 a′′′′′′′ Seven-lined 26579.501


Common scales beginning on AEdit

  • A major: A B C D E F G A
  • A natural minor: A B C D E F G A
  • A harmonic minor: A B C D E F G A
  • A melodic minor ascending: A B C D E F G A
  • A melodic minor descending: A G F E D C B A

Diatonic scalesEdit

  • A Ionian: A B C D E F G A
  • A Dorian: A B C D E F G A
  • A Phrygian: A B  C D E F G A
  • A Lydian: A B C D E F G A
  • A Mixolydian: A B C D E F G A
  • A Aeolian: A B C D E F G A
  • A Locrian: A B  C D E  F G A

Jazz melodic minorEdit

See alsoEdit