A Complete Reference to Over 7 000 Chords. An alternate tuning is created when one or more strings of the guitar are tuned to notes that differ from standard tuning. This book is designed to familiarize you with chord shapes while playing in some of the most common alternate tunings such as: Open D Open G Open Gm Open A Open E Open Em Open C Drop D Double Drop D Dsus4 and more. Includes info on chord construction and easy-to-read diagrams.