A♭1 : 51.913 Hz
A♭1 (A-flat 1) is 51.913 Hz in standard equal temperament at A=440 Hz. It is MIDI note number 32. This is the flat spelling of this pitch, see also G♯1.
A♭ is the tonic of A♭ major (4 flats) and appears frequently in Romantic-era piano literature and jazz standards.
A♭1 Frequency in All Tuning Systems
| Temperament | Frequency (Hz) | Cents from Equal | Common Usage |
|---|---|---|---|
| Equal Temperament | 51.913 Hz | 0.00 | Modern standard; piano, fretted instruments |
| Pythagorean Tuning | 52.207 Hz | +9.78 | Medieval/early music; string ensemble open fifths |
| Just / Pure | 52.325 Hz | +13.69 | A cappella vocal, barbershop, Renaissance |
| Meantone 1/3 Comma | 51.234 Hz | -22.79 | Renaissance vocal music in minor keys |
| Meantone 1/4 Comma | 51.403 Hz | -17.09 | Renaissance keyboard, early Baroque organ |
| 1/6 SC - Attenuated | 51.566 Hz | -11.61 | Baroque orchestral ensemble compromise |
| Kellner's Bach | 52.030 Hz | +3.90 | Bach keyboard reconstruction |
| Kirnberger III | 52.030 Hz | +3.90 | Classical-era keyboard, keys near C major |
| Vallotti | 52.030 Hz | +3.90 | Baroque/Classical orchestral tuning |
| Werckmeister III | 52.030 Hz | +3.90 | Baroque keyboard; Bach contemporaries |
| Werckmeister IV | 51.854 Hz | -1.97 | Baroque keyboard, strong key contrast |
| Werckmeister V | 51.854 Hz | -1.97 | Specialized Baroque keyboard |
Positive cents = sharper than equal temperament. Negative cents = flatter. 100 cents = 1 semitone.
A♭1 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) | 51.913 Hz | US, UK, and most modern ensembles worldwide |
| A = 442 Hz | 52.149 Hz | Many European orchestras; France, Germany |
| A = 443 Hz | 52.267 Hz | Berlin Philharmonic; some US orchestras |
| A = 432 Hz | 50.969 Hz | Alternative tuning; Baroque revival |
| A = 415 Hz (Baroque) | 48.963 Hz | Historically-informed Baroque performance |
f = f_at_A440 × (concert_pitch / 440)
Instruments That Play A♭1
A♭1 (51.913 Hz) falls within the comfortable playing range of 11 instruments.
A♭1 and G♯1: Enharmonic Equivalents
A♭1 and G♯1 are enharmonic equivalents, they sound identical at 51.913 Hz but are written differently depending on the musical context.
When to Write A♭1
A♭ is the tonic of A♭ major (4 flats) and appears frequently in Romantic-era piano literature and jazz standards.
Composers write A♭ in flat-key contexts, as the tonic of A♭ major, the 4th degree of E♭ major, or a chromatic passing tone in flat keys. Chopin, Schubert, and Debussy wrote extensively in A♭ major. In jazz lead sheets, A♭ is the standard spelling.
Major scales containing A♭1: A♭ major (tonic), D♭ major (5th), E♭ major (4th).
Minor scales containing A♭1: F minor (3rd), C minor (6th), B♭ minor (7th).
A♭1 in Instrument Literature
A♭ is one of the most comfortable keys for B♭ clarinet and trumpet (concert A♭ = written B♭). Horn players in orchestral settings read A♭ regularly. Jazz pianists use A♭ major frequently, and it is a staple key in the Great American Songbook repertoire.
In fixed-do solfège, A♭ is sung as "le" (♭6). In A♭ major with moveable do, it is "do" (the tonic).
How G♯1 Differs in Context
While G♯1 sounds identical to A♭1, it belongs to a different set of keys and carries different harmonic implications.
G♯1: G♯ is the leading tone in A major and a key-signature accidental in sharp keys from A major onward.
Major scales: A major (7th / leading tone), E major (3rd), B major (6th), F♯ major (2nd), C♯ major (5th).
Minor scales: C♯ minor (5th), G♯ minor (tonic), F♯ minor (2nd), E minor (3rd, melodic ascending).
String players encounter G♯ in A major, one of the most important keys for violin repertoire. The A major scale (with its 3 sharps: F♯, C♯, G♯) is fundamental to string technique. Pianists see G♯ in Beethoven sonatas and other Classical-era works in A and E major.
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♭1 Varies Across Tuning Systems
A♭1 shows a maximum deviation of -22.79 cents in Meantone 1/3 Comma compared to equal temperament. This 23-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♭1 is tuned flatter than equal temperament, reflecting this system's approach to distributing the Pythagorean comma across the chromatic scale.
4 of the 15 non-equal temperaments deviate by more than 10 cents for A♭1, making this note one where tuning system choice has a meaningful impact on pitch.
A♭1 Across All Tuning Systems
Explore how A♭1 is tuned in each historical temperament system. Each tuning system gives A♭1 a slightly different frequency, affecting the harmonic character of chords and melodies.
A♭1 in Historical Temperament Systems
Explore how A♭1 (51.913 Hz in equal temperament) is tuned in each of the 15 historical non-equal temperament systems. Each system places A♭1 at a slightly different frequency based on its mathematical basis.
Tune A♭1 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.
