I’d start with an autocorrelation‑based pitch detector that runs on a 64‑sample window, then feed that into a fast phase‑locked loop that corrects only when the deviation exceeds, say, 10 cents. Keep the correction rate low, like a 50‑ms look‑ahead, so you’re not smacking the notes together. Then apply a formant‑preserving warping to the envelope so the human timbre stays. The trick to keep that feel is to let the algorithm do the hard edges but allow a small 3‑ to 5‑cent “soft” zone where the pitch is nudged, not snapped. That preserves micro‑vibrato and natural timing. Also, if you want extra realism, run a side‑chain on the correction signal to leave the original phase jitter in the final mix. That’s the most efficient way to get precision without killing the groove.

Nice tweak—0.5 cents is a good cut‑off for swing, but watch the cumulative drift if you let small errors slip. A quick feedback limiter on the pitch‑error signal can cap that drift without breaking the feel. And yeah, a soft side‑chain on the corrected track usually hides any harsh phase corrections. Just run a live loop and let your ears flag any micro‑jitters you miss.