The “Ordinary” of the mass consists of the main sung parts that don’t change: the Kyrie, Gloria, Credo, Sanctus, and Agnus Dei.
The propers are the parts of the mass that change every day: the Introit (Entrance Chant), Gradual (nowadays commonly replaced with the Responsorial Psalm), Alleluia, Offertory, and Communion chants.
Things we will do when we have time. These pages are often in a “drafty” state.