Anyone who wants to learn Gregorian Chant, the Chant of the Catholic Church, will want a copy of this book. It begins with the basics and has many exercises to help those who wish to sing this sacred chant learn the various intervals and how to sing them properly. A chapter is devoted to harmonizing on the organ to accompany the holy chant of the Church. Priests will find this useful to learn how to chant their part in the Missale Romanum. The Liber Usualis will also become simpler to use and even the most complicated Gradual will soon become easy for the schola. This work is good for the simple choir to the most advanced cantors. St. Alphonsus writes: "a single bad book will be sufficient to cause the destruction of a monastery." Pope Pius XII wrote in 1947 at the beatification of Blessed Maria Goretti: "There rises to Our lips the cry of the Saviour: 'Woe to the world because of scandals ' (Matthew 18:7). Woe to those who consciously and deliberately spread corruption-in novels, newspapers, magazines, theaters, films, in a world of immodesty " We at St. Pius X Press are calling for a crusade of good books. We want to restore 1,000 old Catholic books to the market. We ask for your assistance and prayers. This book is a photographic reprint of the original The original has been inspected and many imperfections in the existing copy have been corrected. At Saint Pius X Press our goal is to remain faithful to the original in both photographic reproductions and in textual reproductions that are reprinted. Photographic reproductions are given a page by page inspection, whereas textual reproductions are proofread to correct any errors in reproduction.