"... other things being equal, it [Gregorian Chant] should be given pride of place in liturgical services." (Vatican II, Sacrosanctum Concilium, 116)
My conversion to the Catholic Church started with the joyful discovery of sacred polyphony and Gregorian Chant, while I was a teenager living in Bombay. The chief means of my education in chant was a little black book I stumbled across in the library at St. Xavier's College (where I studied for five years, from 11th grade through college). It was a 1910 edition of "A Manual of Gregorian Chant According to the Solesmes Books." I read it eagerly, and used it to learn how to read Gregorian notation. Certain books could be checked out for a semester at a time, and I'm pretty sure, that every semester of my stay at St. Xavier's, this little book was in my possession. It was the description of Dom Gueranger in this book that was my first exposure to the Mass (along with copies of old, Latin-English pew missals, in another dusty corner of the library. These, however, were not able to be checked out, alas). The first prayer that I ever memorized, was the Gloria, in Latin. Eventually, I would end up going to the beautiful college chapel at least once a day, and pray the Gloria. I did not know any other prayers!