Here is a completely unrealistic but impossibly enticing idea. Let's all stop everything for one year and study chant using this book: Music Fourth Year: Gregorian Chant According to Principles of Dom Andre Mocquereau. The introduction is by Dom Mocquereau himself. It is sponsored and hosted by the Church Music Association of America.
I can't really find the words to describe what a treasure this is: the perfect merging of art, science, and pedagogy in service of beauty and the faith. I feel overwhelmed and humbled by it. There is something to learn on every page.
How can we not be in awe of that generation of musicians who actually studied this material in detail? So much has been lost, and yet thanks to the medium of the web and the work of so many, there is reason for hope that someday material like this will again be taught in schools and seminaries, and that there will be workshops all year that explore this chapter by chapter.
In any case, the scan is high resolution and very beautiful, a higher quality than any edition you might find in a library because the pages are pure white. The download takes a while so please put it on your hard drive.
Since we can't all take off a year, perhaps someone somewhere will establish a special online forum for Ward Studies. Someday. Maybe soon. I will be the first student.