The leading cause of poor congregational singing in the typical Catholic parish is the amplification of one (or more) voices using a microphone.
No single voice or group of voices should be amplified over that of the people or the organ. For example, when one listens to a good choir, no single voice sings over the choir. Otherwise, the cohesive structure of the choir is pulled apart. When one sings in a choir, one abandons self-identity and joins a collective identity. Likewise, when we congregate for Holy Mass, we abandon self-identity and become the collective Body of Christ. For this reason, according to the United States Conference of Catholic Bishops (USCCB), Sing to the Lord (par. 38), "In order to promote the singing of the liturgical assembly, the cantor's voice should not be heard above the congregation."
No doubt, wheels are turning in your head. “But nobody will sing!” “How will we know when to sing?” Hold those thoughts. First, what we must learn in our parish is that the congregation is the main choir.
Yes, there exists a subset of parishioners who meet regularly to learn more specialized music from a teacher (Mr. Cochrane). In our culture, we have come to say this is the choir. But in fact, they are singing scholars (schola cantorum), students of church music who learn, rehearse, and sing more difficult music not easily attainable by the average parishioner. However, it is you, seated in the church nave, who make up the main choir. Now you can tell all your friends that you sing in the church choir!
Train yourself to listen to the collective voice of the congregation juxtaposed with the organ. Allow your singing confidence to grow!