Michael E. Lawrence posts this at the New Liturgical Movement:
It is not uncommon to see an article from time to time which laments the contemporary songs used at Mass in most places. "What happened to all the great hymns of yesterday?" is often a question asked in anguish in such publications.
Little ink seems to be spilled, however, over the treasure that the widespread use of hymns has seemingly buried--the Proper chants of the Mass (Introit, Offertory, and Communion; the Gradual and Alleluia are a bit different and will be discussed below). It is quite probable that most Catholics are unaware of the Propers and that they would be surprised to find out that the only hymns integral to the Mass itself are the Gloria and the several Sequences that occur throughout the year. Even many Catholics who consider themselves to be traditional are perfectly content with using hymns at the Mass in place of the Propers.
Click here to read the rest of the story. It's an excellent read.