The day program that I work at purchased a really cool Birdsong guide. It has a collection of about seventy- five birds from Eastern and Central North America. The clients absolutely love this book as do the staff like myself who have an intense interest in mother nature. The Cornell lab of Ornithology/Macaulay Library was responsible for the huge amount of bird songs and all the pictures of the individual types of birds. This is an incredible work of art that obviously took tons of exhaustive research. The author is on the staff at Cornell University and has been involved in the study of birdsong for over 40 years. There is an incredible audio module attached to this book that matches up with the pictures and history of the various birds. I have many birds that hang around my house and enjoy my birdfeeders. This has given me much knowledge of what the various species sound like and I have to tell you that definitely got the song right in this book. All in all an incredible piece of work for anyone who has interest in this area. This is a book that should really sell for much more money than it does.