The reason I wrote this series is that, as someone who plays the guitar to a certain extent, I sometimes get stuck musically. This is a common situation for guitarists. If you play only the pentatonic scale from the beginning, you may get tired of that sound, and there may be times when you want to play another style of music. Sometimes, you may feel like something is missing with just the pentatonic scale. This book can help you get out of that situation. It is a book based on my experience of practicing alone for a long time and teaching many students. I am sure that this book can help you get out of the above situation.