From the wise and charming Sacred Miscellany of the subject of "getting" the PIPs to sing:
Last evening I listened, for what seems the upteenth time since I began working as a musician in Catholic Churches, to a discussion of how it is IMPERATIVE (all caps deliberate here) for the congregation to sing everything. We must work and work to make them want to sing it. And if they don't want to sing, we will tell them they must - that they are there to sing and enjoy singing too. And that Vatican II says they must. So there!
Leaving aside the exaggeration of conciliar and later documents which is usually accompanied by a distorted history of music in Christian worship for at least 1,000 years, why would we think it is the role of musicians to dictate the emotions of the congregation? Because every time I hear this little speech, I hear how the people must learn to love singing and feel good while they're doing so. And any resistance on their part is childish, backward, petty, and probably a sign that they have retrograde opinions on almost everything else.
Well, I disagree. Surprised, aren't you? Actually, I ask lots of people how they feel about singing at Mass. Just regular people in the course of ordinary conversations if my work as a church organist comes up. News flash! Many people don't like to sing some of the time or all of the time. They have trouble carrying a tune in the first place. Quite honestly, there are people whose voices are a bane to those around them. Perhaps they don't agree with the sentiments of a particular hymn. In many cases, they find the music too difficult in terms of range or syncopation. And sometimes they just don't want to.
And that's their right. Use singable music for the Ordinary and only switch it out a few times a year. Encourage without browbeating or guilt-tripping for that. On everything else, let the choir and those who wish to sing with them take care of it. Leave those other folks be - and let your singing be a beauty they can drink in.