Our major work for the first half of 2011 will be the St Cecilia Mass, or Messe Solennelle, by Charles Gounod. The Wikipedia page notes that “This work was first performed, in its entirety, for the church of Saint Eustache in Paris on Saint Cecilia’s Day, November 22, 1855; from this rendition dates Gounod’s fame as a noteworthy composer.”
The score we are using is from the Choral Public Domain Library (CPDL), hosted on ChoralWiki. The copyright to this version of the score is held by CPDL under a license that guarantees everyone’s freedom to share and perform public domain music. There is a page dedicated to the St Cecila Mass where you can find PDF copies of the score as well as MIDI training files.