So I figured out an easy way to change the initial letter of your chant in Gregorio that doesn't involve weird TeX coding. So with the help of a page at CC Watershed, the gaudium-mundo blog, and some encouragement (prodding?) from some fellow choir members, I present to you the fruits of my spare time while staying up late trying to get the kiddo down to sleep. It prints out nicely in booklet form on Letter-sized paper.