VCV-Rack 2 is a freely available modular software synthesizer. VCV-Rack simulates a Eurorack that can be internally connected to virtual and even real MIDI devices via both USB and MIDI connections. By default, VCV-Rack includes various modules in the form of VCOs, LFOs, mixers and many more. There is also a wide range of additional installable modules called plugins. VCV-Rack 2 can also be used as a VST plugin in a DAW. The successful author Erik Bartmann describes on more than 310 pages (DinA4 format) with numerous four-color screenshots, photos and illustrations the installation and use of the modular synthesizer. He also sheds light on the physical and musical background of electronic sound generation. Numerous modules and plugins are presented in depth in the book. The entry into the world of modular synthesizers is easy and free with VCV-Rack. If you don't really know yet how everything works in a modular synthesizer and which possibilities of extensions there are, this software solution is perfect for you. If you are seriously interested in the world of modular synthesizers and don't want to spend money on hardware for the time being, you can't get around VCV-Rack. The knowledge and skills gathered here can be fully transferred and applied to a modular synthesizer consisting of physical hardware.