nova-organi-harmonia
LilyPond transcription of the Nova Organi Harmonia
http://www.ccwatershed.org/blog/2013/aug/17/nova-organi-harmonia/
Organ accompaniments for Gregorian Chant
Special thanks to "cantorconvert" for getting this started:
http://forum.musicasacra.com/forum/discussion/8743/mass-i-noh-lilypond/p1
Special thanks to Jeff Ostrowski (et al.) for working to get the NOH published online in the first place.
NOTE
This project is in its infancy, and looking for volunteers. Please contact us if you'd like to help.