This book guides readers through the process of developing synthesizer modules using VCV Rack and its open-source C++ API. It covers everything from elementary to more engaging examples, with practical topics related to releasing plugins and managing complex graphical user interaction. The book also includes exercises and example patches in each chapter, making it a recommended reading for undergraduate and postgraduate students of audio engineering, music technology, computer science, electronics, and related courses; audio coding and do-it-yourself enthusiasts; and professionals looking for a quick guide to VCV Rack.