Explore four approaches to pitch-shifting music and time-stretching in this 44-minute conference talk from the Audio Developer Conference (ADC22). Dive into intuitive visual explanations, code examples, and audio demonstrations, starting with a simple overlap-add approach. Investigate the mechanics of FFT-based effects and frequency-domain techniques before concluding with the design used in a new open-source polyphonic pitch/time C++ library. Gain insights from Geraint Luff, head of Signalsmith Audio, as he shares his expertise in audio algorithm design and implementation.