A♯ (musical note)

For other uses, see A♯.

A♯ (A-sharp; also called la dièse) is the eleventh semitone of the solfège. In some countries (where B is known as H), it is also called B.

This note lies a chromatic semitone above A and a diatonic semitone below B, thus being enharmonic to si bémol or B♭ (B-flat).

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 466.164Hz. See pitch (music) for a discussion of historical variations in frequency.

Designation by octave

Scientific designation	Helmholtz designation	Octave name	Frequency (Hz)
A♯−1	A♯͵͵͵ or ͵͵͵A♯ or AAAA♯	Subsubcontra	14.568
A♯0	A♯͵͵ or ͵͵A♯ or AAA♯	Subcontra	29.135
A♯1	A♯͵ or ͵A♯ or AA♯	Contra	58.27
A♯2	A♯	Great	116.541
A♯3	a♯	Small	233.082
A♯4	a♯′	One-lined	466.164
A♯5	a♯′′	Two-lined	932.328
A♯6	a♯′′′	Three-lined	1864.655
A♯7	a♯′′′′	Four-lined	3729.31
A♯8	a♯′′′′′	Five-lined	7458.62
A♯9	a♯′′′′′′	Six-lined	14917.24
A♯10	a♯′′′′′′′	Seven-lined	29834.481

Scales

Common scales beginning on A♯

• 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 scales

• 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 minor

• A♯ ascending melodic minor: A♯ B♯ C♯ D♯ E♯ F G A♯
• A♯ Dorian ♭2: A♯ B C♯ D♯ E♯ F G♯ A♯
• A♯ Lydian augmented: A♯ B♯ C D E F G A♯
• A♯ Lydian dominant: A♯ B♯ C D E♯ F G♯ A♯
• A♯ Mixolydian ♭6: A♯ B♯ C D♯ E♯ F♯ G♯ A♯
• A♯ Locrian ♮2: A♯ B♯ C♯ D♯ E F♯ G♯ A♯
• A♯ altered: A♯ B C♯ D E F♯ G♯ A♯

See also

• B♭ (musical note), an enharmonic note
• Piano key frequencies
• A-sharp major
• A-sharp minor
• Root (chord)