A♭ (musical note)


A 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 is approximately 415.305 Hz. See pitch for a discussion of historical variations in frequency.
A/G is the only note to have only one other enharmonic.

Designation by octave

Scales

Common scales beginning on A