There is nothing Catholic that is not rooted in the Old Testament. Our Catholic faith did not spring up out of nowhere, but out of the faith of Abraham, Isaac and Jacob.
This is true liturgically speaking, as we have a tabernacle, altar and priesthood in the New Covenant, similar to the Old Covenant. We also have Gregorian chant, which is rooted in Old Covenant worship. The Psalms were not merely read, but chanted in public worship of God, which Jesus himself participated in as a child.
This chant was more fully developed in the Catholic Church and became what we now refer to as Gregorian chant. I’ve listened to many types of chant, but none quite as beautiful as Gregorian.
Pope Benedict XVI has encouraged the faithful to reacquaint themselves with this chant and use it liturgically; we want to follow our Supreme Pontiff’s lead.
Read more from Sister Rosalind Moss at the NGReg