D♭3 — 138.591 Hz
D♭3 (D-flat 3) is 138.591 Hz in standard equal temperament at A=440 Hz. It is MIDI note number 49. This is the flat spelling of this pitch — see also C♯3.
D♭ is the tonic of D♭ major (5 flats) and appears as a scale degree in several flat keys.
D♭3 Frequency in All Tuning Systems
| Temperament | Frequency (Hz) | Cents from Equal | Common Usage |
|---|---|---|---|
| Equal Temperament | 138.591 Hz | 0.00 | Modern standard; piano, fretted instruments |
| Pythagorean Tuning | 139.219 Hz | +7.83 | Medieval/early music; string ensemble open fifths |
| Just / Pure | 139.534 Hz | +11.74 | A cappella vocal, barbershop, Renaissance |
| Meantone 1/3 Comma | 137.190 Hz | -17.59 | Renaissance vocal music in minor keys |
| Meantone 1/4 Comma | 137.500 Hz | -13.68 | Renaissance keyboard, early Baroque organ |
| 1/6 SC - Attenuated | 137.821 Hz | -9.65 | Baroque orchestral ensemble compromise |
| Kellner's Bach | 138.748 Hz | +1.96 | Bach keyboard reconstruction |
| Kirnberger III | 138.631 Hz | +0.50 | Classical-era keyboard, keys near C major |
| Vallotti | 138.748 Hz | +1.96 | Baroque/Classical orchestral tuning |
| Werckmeister III | 138.748 Hz | +1.96 | Baroque keyboard; Bach contemporaries |
| Werckmeister IV | 138.122 Hz | -5.87 | Baroque keyboard, strong key contrast |
| Werckmeister V | 138.748 Hz | +1.96 | Specialized Baroque keyboard |
Positive cents = sharper than equal temperament. Negative cents = flatter. 100 cents = 1 semitone.
D♭3 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) | 138.591 Hz | US, UK, and most modern ensembles worldwide |
| A = 442 Hz | 139.221 Hz | Many European orchestras; France, Germany |
| A = 443 Hz | 139.536 Hz | Berlin Philharmonic; some US orchestras |
| A = 432 Hz | 136.071 Hz | Alternative tuning; Baroque revival |
| A = 415 Hz (Baroque) | 130.717 Hz | Historically-informed Baroque performance |
f = f_at_A440 × (concert_pitch / 440)
Instruments That Play D♭3
D♭3 (138.591 Hz) falls within the comfortable playing range of 33 instruments.
D♭3 and C♯3 — Enharmonic Equivalents
D♭3 and C♯3 are enharmonic equivalents — they sound identical at 138.591 Hz but are written differently depending on the musical context.
When to Write D♭3
D♭ is the tonic of D♭ major (5 flats) and appears as a scale degree in several flat keys.
Composers write D♭ when the harmonic context involves flat keys — for instance, as the tonic in D♭ major or as the 4th degree in A♭ major. In descending passages within flat keys, D♭ reads more naturally than C♯.
Major scales containing D♭3: D♭ major (tonic), G♭ major (5th), A♭ major (4th).
Minor scales containing D♭3: B♭ minor (3rd), F minor (6th), E♭ minor (7th).
D♭3 in Instrument Literature
Wind and brass players encounter D♭ frequently. B♭ instruments (clarinet, trumpet) read it in their common flat-side keys, and French horn parts in flat keys use it regularly.
In fixed-do solfège, D♭ is sung as "ra" (♭2). In D♭ major with moveable do, it is "do" (the tonic).
How C♯3 Differs in Context
While C♯3 sounds identical to D♭3, it belongs to a different set of keys and carries different harmonic implications.
C♯3: C♯ is the leading tone in D major and a key-signature accidental in all sharp keys from D major onward.
Major scales: D major (7th / leading tone), A major (3rd), E major (6th), B major (2nd), F♯ major (5th), C♯ major (tonic).
Minor scales: F♯ minor (5th), C♯ minor (tonic), G♯ minor (4th), B minor (2nd).
String instruments (violin, viola, cello) encounter C♯ frequently in sharp keys like D major and A major, which are natural keys for bowed strings. Guitarists use C♯ in keys like 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 D♭3 Varies Across Tuning Systems
D♭3 shows a maximum deviation of -17.59 cents in Meantone 1/3 Comma compared to equal temperament. This 18-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, D♭3 is tuned flatter than equal temperament, reflecting this system's approach to distributing the Pythagorean comma across the chromatic scale.
3 of the 15 non-equal temperaments deviate by more than 10 cents for D♭3, making this note one where tuning system choice has a meaningful impact on pitch.
D♭3 Across All Tuning Systems
Explore how D♭3 is tuned in each historical temperament system. Each tuning system gives D♭3 a slightly different frequency, affecting the harmonic character of chords and melodies.
D♭3 in Historical Temperament Systems
Explore how D♭3 (138.591 Hz in equal temperament) is tuned in each of the 15 historical non-equal temperament systems. Each system places D♭3 at a slightly different frequency based on its mathematical basis.
Tune D♭3 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.
