C4 — 261.626 Hz
C4 (C4) is 261.626 Hz in standard equal temperament at A=440 Hz. It is MIDI note number 60.
C4 Frequency in All Tuning Systems
| Temperament | Frequency (Hz) | Cents from Equal | Common Usage |
|---|---|---|---|
| Equal Temperament | 261.626 Hz | 0.00 | Modern standard; piano, fretted instruments |
| Pythagorean Tuning | 260.740 Hz | -5.87 | Medieval/early music; string ensemble open fifths |
| Just / Pure | 261.626 Hz | 0.00 | A cappella vocal, barbershop, Renaissance |
| Meantone 1/3 Comma | 263.703 Hz | +13.69 | Renaissance vocal music in minor keys |
| Meantone 1/4 Comma | 263.181 Hz | +10.26 | Renaissance keyboard, early Baroque organ |
| 1/6 SC - Attenuated | 262.663 Hz | +6.85 | Baroque orchestral ensemble compromise |
| Kellner's Bach | 263.047 Hz | +9.38 | Bach keyboard reconstruction |
| Kirnberger III | 263.181 Hz | +10.26 | Classical-era keyboard, keys near C major |
| Vallotti | 262.514 Hz | +5.87 | Baroque/Classical orchestral tuning |
| Werckmeister III | 263.404 Hz | +11.73 | Baroque keyboard; Bach contemporaries |
| Werckmeister IV | 262.810 Hz | +7.82 | Baroque keyboard, strong key contrast |
| Werckmeister V | 262.514 Hz | +5.87 | Specialized Baroque keyboard |
Positive cents = sharper than equal temperament. Negative cents = flatter. 100 cents = 1 semitone.
C4 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) | 261.626 Hz | US, UK, and most modern ensembles worldwide |
| A = 442 Hz | 262.815 Hz | Many European orchestras; France, Germany |
| A = 443 Hz | 263.409 Hz | Berlin Philharmonic; some US orchestras |
| A = 432 Hz | 256.869 Hz | Alternative tuning; Baroque revival |
| A = 415 Hz (Baroque) | 246.760 Hz | Historically-informed Baroque performance |
f = f_at_A440 × (concert_pitch / 440)
Instruments That Play C4
C4 (261.626 Hz) falls within the comfortable playing range of 55 instruments.
Why C4 Varies Across Tuning Systems
C4 shows a maximum deviation of +13.69 cents in Meantone 1/3 Comma compared to equal temperament. This 14-cent difference reflects how different tuning philosophies prioritize interval purity over equal distribution.
In Meantone 1/3 Comma, C4 is tuned sharper than equal temperament to achieve purer intervals with nearby notes in the tuning system's favored keys.
4 of the 15 non-equal temperaments deviate by more than 10 cents for C4, making this note one where tuning system choice has a meaningful impact on pitch.
C4 Across All Tuning Systems
Explore how C4 is tuned in each historical temperament system. Each tuning system gives C4 a slightly different frequency, affecting the harmonic character of chords and melodies.
C4 in Historical Temperament Systems
Explore how C4 (261.626 Hz in equal temperament) is tuned in each of the 15 historical non-equal temperament systems. Each system places C4 at a slightly different frequency based on its mathematical basis.
Tune C4 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.
