There are some video links in the first page of this e-book, Well if you watch them and take note of all the musicians piano, banjo, fiddle everything, you are capable of playing everything in these videos, all the instruments, everything. Just like they are doing.
Those who already play guitar all over the neck, who already know how to find the key and understand how scales and chords work, so if you want to learn another instrument then 90% of the work is already done. It will be really easy. This book will show you how. Then you can be like me; able to play anything.