Sometimes it’s tricky to get our fellow Catholics to understand that the music that we are hearing 95% of the time in our parish churches at Mass on Sundays is not the music Holy Mother Church intends. For example, we are called to use the organ predominantly as an instrument for our worship music (and secular instruments such as guitars not at all), and to sing only Sacred Music (that is preferably based on plainchant) because it is elevated above the music we hear outside in the secular world. Most people don’t know this, but all Catholics are asked to know some basic Latin chants of the Liturgy (see the papal document Jubilate Deo, issued in 1974).
Because the Holy Sacrifice of the Mass is the “source and summit” of our Christian life, the Church has very high standards for what we should be hearing and singing. Here is a document that gives information and resources for Catholics to understand the place of Sacred Music in the Church:
(I welcome feedback on this! This is a tough subject to talk about in parishes, and it should always be done with charity and sensibility: love for God, love for the Church, love for her Sacred Liturgy, and most of all, love for the person to whom you are conversing!)