During the prelude of my parish’s funeral Mass today, one of my singers rendered this chestnut of modern sacred music as a solo.
It brought to mind my experience of that piece thirty-plus years ago in another parish. During my grad school days, week after week at the parish’s Thursday Night Folk Mass (yes, they were still calling it that–too radical for Sunday music at first) the entire assembly, two-hundred to three-hundred strong, sang this setting unaccompanied with full gusto. Hands together, hands uplifted–the whole charismatic, happy-clappy thing. Never before and never since have I experienced this particular piece done in this way.
It brings to mind a sentiment I often read online. (Real life not so much.) Catholics in the pews can’t or don’t sing (fill in the bank). Chant. Syncopated P&W. Latin. Strummed music. Piano-accompanied music. New songs. Old songs. My opinion: poppycock, to use the theological term.
People will sing anything–or give it a prayerful try–if they have something to sing about. Their faith. Their sense of community.
I bring that optimism to music ministries I lead. We will sing any text that contributes to a sense of liturgy and mysticism and that is focused on telling the story of God. The best music will work, regardless of genre or style. Nothing is unsingable. Unless, sadly, there is weak or no faith. In that case, nothing is singable.
Catholic Sensibility 
Albert Hay Mallotte’s “Lord’s Prayer”, don’t know that I would call it a chestnut, but it was certainly used a lot in (mostly Protestant) weddings and funerals in the 50s and 60s. Been awhile since I have heard it. Agree with you that “People will sing anything, -or give it a prayerful try- if they have something to sing about.” I get tired of reading that Catholics aren’t any good at singing hymns, so they ought to just give it up. And do Latin propers , or something. That doesn’t square witn my lived experience. If it has a singable tune, and resonates with their faith, they will sing it.