The biggest complaint about parish music today is that it is too loud, too busy, too ego-driven, and too jazzed up. None of this is necessary, and neither is the Gregorian repertoire the only cure. The transition to quiet and sacred music can come with easy settings that are quick to teach and learn, mostly in English at the outset. Vernacular plainsong can be wonderful, especially for parishes that are looking for periods of quiet reflection, using voice only settings that require no instruments. The idea is to prepare the way for more complex settings in Latin later on.
This setting of Ambrosian chant was adapted by Arlene Oost-Zinner for use at the 2008 Sacred Music Colloquium in Chicago. Feel free to print and use in your parish. Here is a PDF file.