So I went online to try to find mp3 versions of the hymns we sing at Mass, and it seems as if there are multiple ways to sing certain hymns (you know, same words, different tune). It seems as if my parish follows the Mass of Light versions of the hymns.
So… is like the Mass of Light like a sub-type of the OF Mass? What is the Mass of Light?
It’s a Mass setting of the Ordinary of the Mass (Gloria, Sanctus, Memorial Acclamation, Amen and Agnus Dei). Bear in mind that the sung prayers of the Mass are not merely hymns and that these (the ones named in parenthesis) need to match the official texts of the Church word for word. This was stipulated in Liturgiam Authenticam (2001) and again, by the Congregation for Divine Worship and the Discipline of the Sacraments (2008) when it released the new English translation of the Mass.
In case it wasn’t clear from the answer above, anyone can compose a setting of the ordinary of the Mass – those are the parts that generally stay the same from week to week: the Kyrie, Gloria, Sanctus, memorial acclamation, “Great Amen,” etc. A collection of musical versions of those pieces that are intended to go together is what people call a “Mass setting.” But the composer can put any name he likes on it (just like if he wrote a hymn), and the general custom for naming a Mass setting is to call it “Mass of ____” (or in Latin, “Missa ____”). So “Mass of Light” is not a sub-type of the OF Mass, it’s the name a composer chose for his version of the musical settings to certain parts of the Mass.
And while there could be more than one setting titled “the Mass of Light,” the one your parish is probably using is by David Haas. It’s also one of his less objectionable efforts, IMO; I wouldn’t want it at the Mass, but as music, it has a cool Liquid Tension Experiment feel to it.