TL;DR
Sid Rockett built an open-source granular synthesizer called Arena Digitalis using an Arduino Nano R4. This device processes audio samples by chopping them into tiny “grains” and rearranging them, creating unique sound textures that are popular among experimental musicians. Granular synthesizers are typically expensive due to the memory and processing power required for real-time audio manipulation, but the Nano R4 offers a cost-effective solution with its 32kB of RAM and 48MHz clock speed.