Design of a pitch quantization and pitch correction system for real-time music effects signal processing

This paper describes the design of a practical, real-time pitch quantization system intended for digital musical effects signal processing. Like most modern pitch quantizers, this system can be used to pitch correct and even reharmonize out-of-tune singing to alternative musical scales simultaneously (e.g. major, minor, diminished, etc.) Pitch Quantization can also be intentionally exaggerated to produce distinctive effects processing which results in an emotionally inflected and/or “robotic” sound. This system uses intentionally simple signal processing algorithms which make real-time processing possible on constrained devices. In particular, we employ tools such as an octave resolver and range limiter, grain boundary expansion and contraction, and transient detection to enhance the performance of our system.