A♯8 : 7458.620 Hz
A♯8 (A-sharp 8) is 7458.620 Hz in standard equal temperament at A=440 Hz. It is MIDI note number 118. This is the sharp spelling of this pitch, see also B♭8.
A♯ is the leading tone in B major and appears as a key-signature accidental only in sharp keys with 5 or more sharps.
A♯8 Frequency in All Tuning Systems
| Temperament | Frequency (Hz) | Cents from Equal | Common Usage |
|---|---|---|---|
| Equal Temperament | 7458.620 Hz | 0.00 | Modern standard; piano, fretted instruments |
| Pythagorean Tuning | 7416.604 Hz | -9.78 | Medieval/early music; string ensemble open fifths |
| Just / Pure | 7534.816 Hz | +17.60 | A cappella vocal, barbershop, Renaissance |
| Meantone 1/3 Comma | 7556.102 Hz | +22.48 | Renaissance vocal music in minor keys |
| Meantone 1/4 Comma | 7532.700 Hz | +17.11 | Renaissance keyboard, early Baroque organ |
| 1/6 SC - Attenuated | 7509.328 Hz | +11.73 | Baroque orchestral ensemble compromise |
| Kellner's Bach | 7499.141 Hz | +9.38 | Bach keyboard reconstruction |
| Kirnberger III | 7502.954 Hz | +10.26 | Classical-era keyboard, keys near C major |
| Vallotti | 7483.953 Hz | +5.87 | Baroque/Classical orchestral tuning |
| Werckmeister III | 7509.328 Hz | +11.73 | Baroque keyboard; Bach contemporaries |
| Werckmeister IV | 7500.874 Hz | +9.78 | Baroque keyboard, strong key contrast |
| Werckmeister V | 7475.485 Hz | +3.91 | Specialized Baroque keyboard |
Positive cents = sharper than equal temperament. Negative cents = flatter. 100 cents = 1 semitone.
A♯8 at Different Concert Pitches
The same note varies in frequency depending on the concert pitch standard used by your ensemble.
| Concert Pitch | Frequency (Hz) | Common Usage |
|---|---|---|
| A = 440 Hz (ISO standard) | 7458.620 Hz | US, UK, and most modern ensembles worldwide |
| A = 442 Hz | 7492.523 Hz | Many European orchestras; France, Germany |
| A = 443 Hz | 7509.474 Hz | Berlin Philharmonic; some US orchestras |
| A = 432 Hz | 7323.009 Hz | Alternative tuning; Baroque revival |
| A = 415 Hz (Baroque) | 7034.835 Hz | Historically-informed Baroque performance |
f = f_at_A440 × (concert_pitch / 440)
Instruments That Play A♯8
A♯8 (7458.620 Hz) falls within the comfortable playing range of 1 instrument.
A♯8 and B♭8: Enharmonic Equivalents
A♯8 and B♭8 are enharmonic equivalents, they sound identical at 7458.620 Hz but are written differently depending on the musical context.
When to Write A♯8
A♯ is the leading tone in B major and appears as a key-signature accidental only in sharp keys with 5 or more sharps.
Composers write A♯ only when the harmonic context demands sharp-side spelling, most often as the leading tone in B major or in chromatic passages within sharp keys. Because B♭ is far more common, seeing A♯ signals a very specific tonal context: the note is pulling upward toward B in a sharp key.
Major scales containing A♯8: B major (7th / leading tone), F♯ major (3rd), C♯ major (6th).
Minor scales containing A♯8: D♯ minor (5th), A♯ minor (tonic), G♯ minor (2nd).
A♯8 in Instrument Literature
String players encounter A♯ primarily in B major and F♯ major. Pianists see it in heavily sharped key signatures. A♯ is relatively rare in wind and brass literature, where the same pitch is almost always written as B♭.
In fixed-do solfège, A♯ is sung as "li" (♯6). In B major with moveable do, it is "ti" (the leading tone).
How B♭8 Differs in Context
While B♭8 sounds identical to A♯8, it belongs to a different set of keys and carries different harmonic implications.
B♭8: B♭ is the tonic of B♭ major (2 flats) and is the single most common accidental in Western music, appearing as the first flat in any flat key signature.
Major scales: F major (4th), B♭ major (tonic), E♭ major (5th), A♭ major (2nd).
Minor scales: G minor (3rd), D minor (6th), C minor (7th).
B♭ is the transposition interval for B♭ clarinet, B♭ trumpet, and tenor saxophone, they read C but sound B♭. It is arguably the single most important note for concert band and wind ensemble repertoire. Trombonists and tuba players read B♭ constantly in their native flat keys.
Enharmonic equivalents share the same frequency in equal temperament. In historical temperaments like Pythagorean or meantone, they may differ slightly, see the temperament comparison table above for this note's exact deviations.
Why A♯8 Varies Across Tuning Systems
A♯8 shows a maximum deviation of +22.48 cents in Meantone 1/3 Comma compared to equal temperament. This 22-cent difference is clearly audible to trained musicians and reflects how different tuning philosophies prioritize interval purity over equal distribution.
In Meantone 1/3 Comma, A♯8 is tuned sharper than equal temperament to achieve purer intervals with nearby notes in the tuning system's favored keys.
6 of the 15 non-equal temperaments deviate by more than 10 cents for A♯8, making this note one where tuning system choice has a meaningful impact on pitch.
A♯8 Across All Tuning Systems
Explore how A♯8 is tuned in each historical temperament system. Each tuning system gives A♯8 a slightly different frequency, affecting the harmonic character of chords and melodies.
A♯8 in Historical Temperament Systems
Explore how A♯8 (7458.620 Hz in equal temperament) is tuned in each of the 15 historical non-equal temperament systems. Each system places A♯8 at a slightly different frequency based on its mathematical basis.
Tune A♯8 with precision: Get Tunable.
Tunable supports 15+ tuning systems including equal temperament, Pythagorean, just intonation, and historical well-temperaments. See exact Hz values in real-time as you play.
