The Math of Pitch Shifting
In digital audio, pitch shifting often works by resampling or using complex algorithms like FFT. Regardless of the method, the underlying physics remains the same. Since the musical octave is logarithmic, moving up one semitone means multiplying the frequency by the 12th root of 2 (approx. 1.05946).
Conversion Formula
To find the target frequency based on a shift in cents (where 100 cents = 1 semitone), use:
Target Frequency = Base Frequency × 2^(Cents / 1200)
Common Usage Examples
- Avoiding Phasing: When doubling a vocal track, try shifting one layer up 5 cents and the other down 5 cents. This adds thickness without creating noticeable pitch issues.
- Tuning 808s: If your 808 sample is slightly sharp, use the "Fine Tune" or "Cents" parameter in your sampler to bring it back into perfect tune with your track's root note.