The idea came up to have a Sung Mass for the Feast of the Exaltation of the Holy Cross at a certain upcoming homeschool camp.
Here a dedicated singer/organist runs through the Big Four: Kyrie, Gloria, Sanctus, Agnus Dei:
Here is a good run through of the Kyrie with the written music on the screen:
Here is the first musician singing Credo 1:
The hymns are more added extras rather than essential pieces of a sung Mass. Even though they are in Latin, they are a bit easier to master as the tune is the same for each verse. St Ambrose is credited with inventing hymns to strengthen the faithful.