(Berklee Methods). The Berklee in the Pocket Essential Songwriter is an accessible reference guide that will quickly lead songwriters to ideas that are at the heart of countless hit songs. The tips and strategies jam-packed into this concise guide will help you tackle writer's block and gain fresh insight into the songwriting process. Includes: the 17 chord progressions that are at the heart of the most popular hit songs, guitar charts and keyboard chords showing how to play progressions in all 12 keys, tips to customize essential chord progressions to suit your own songs, contact info for businesses and organizations most important to the working songwriter, and more!