Cello
Authority: Equal Temperament Pitch Frequency Table
Standard cello tuning uses four strings in perfect fifths, low to high: C2, G2, D3, and A3. At A440 concert pitch these correspond to 65.41 Hz, 98.00 Hz, 146.83 Hz, and 220.00 Hz -- the same pitch classes as the viola, just one octave lower.
| String # | Note Name | Scientific Pitch | Frequency (Hz) |
|---|---|---|---|
| 4 (Thickest) | C | C2 | 65.41 Hz |
| 3 | G | G2 | 98.00 Hz |
| 2 | D | D3 | 146.83 Hz |
| 1 (Thinnest) | A | A3 | 220.00 Hz |
History & Tuning Logic
The cello developed in 16th-century Italy alongside the rest of the violin family and inherited that family's fifths-based tuning logic despite sitting an octave below the viola. Its four strings -- C2, G2, D3, A3 -- are pitched exactly one octave below the viola's C3-G3-D4-A4, which is why cellists and violists can read closely related fingering patterns for the same music even though their instruments sound an octave apart.
Like the rest of the violin family, the cello's adjacent strings are tuned a perfect fifth apart, an interval chosen because strings a fifth apart share closely related overtones and resonate sympathetically with each other, reinforcing the instrument's tone. That same fifths logic runs through the violin and viola too; the double bass, tuned in fourths instead, is the outlier of the modern string section.