this book is an overview of everything that was interesting in 70's era modular synthesizers (and therefore, covers 95% of what's interesting with 21st century modular synthesizers). there's a lot to learn here, and while it's a bit of a downer that the example patches are almost all for buchla 200 and/or emu (great for the 50 people that have access to one of those systems) the theory is still applicable to any system, even something like max/msp or csound. i have the second edition in print, not sure it's really worth the going cost. i also can't say for sure whether there's a reason to choose it over the first (which is available online). i can say that it's the definitive book on analog style synthesis and a must-read for anyone who fancies that sort of thing.