Tonal Sight-Singing, the Book is the first of a series of three textbooks that attempt to guide the aspiring musician in confronting the challenges of sight-singing, mainly when dealing with large intervallic skips. This is done through a series of exercises and melodies that are focused on specific scale-degrees and allow us to get to know them (and their role within the tonal system) intimately, in order for us to free ourselves from the need to calculate adjacent intervals. This book focuses mainly on the diatonic collection, and dedicates a chapter to each of the diatonic scale-degrees in major and minor. The future books will take a look at the altered (chromatic) scale-degrees, as well as the subtleties of local harmony and how it affects our perception of each scale-degree.