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 | 260.740 Hz | -5.87 | Medieval/early music; string ensemble open fifths |
| Just Intonation (Major) | 261.626 Hz | 0.00 | A cappella vocal, barbershop, Renaissance |
| Just Intonation (Minor) | 261.626 Hz | 0.00 | Minor-key vocal music, string ensembles |
| Quarter-Comma Meantone | 263.181 Hz | +10.26 | Renaissance keyboard, early Baroque organ |
| Third-Comma Meantone | 263.703 Hz | +13.69 | Renaissance vocal music in minor keys |
| Sixth-Comma Meantone | 262.663 Hz | +6.85 | Baroque orchestral ensemble compromise |
| 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 |
| Kirnberger III | 263.181 Hz | +10.26 | Classical-era keyboard, keys near C major |
| Vallotti | 262.514 Hz | +5.87 | Baroque/Classical orchestral tuning |
| Young (1799) | 262.810 Hz | +7.82 | Classical-era keyboard |
| Bach/Lehman | 262.514 Hz | +5.87 | Bach keyboard works, Well-Tempered Clavier |
| Neidhardt | 262.217 Hz | +3.91 | 18th century keyboard, near-equal alternative |
| Kellner (Bach) | 263.047 Hz | +9.38 | Bach keyboard reconstruction |
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 Third-Comma Meantone compared to equal temperament. This 14-cent difference reflects how different tuning philosophies prioritize interval purity over equal distribution.
In Third-Comma Meantone, 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.
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.