One of the primary aims of singing in any context - whether around a campfire, a birthday table, in a ballpark, caroling through a neighborhood, or at church - is, in fact, the opposite of exclusion, in the idea that communal song can be a great symbol and expression of our unity as a people. In the Christian sense, we don’t sing because we like music or because we like to sing or think music is nice or pretty. We sing because sung prayer has been an indispensable part of the Judeo-Christian tradition from its beginnings in temple and synagogue worship and in scriptures, always as an expression of our unity as a people - for Christians, the unity of the body of Christ.
Some parts of our liturgy and prayers are simply meant to be sung: In the Jewish tradition, psalms of the Old Testament were composed as sung prayer and were accompanied by instruments such as the harp or lyre. In the earliest accounts of Christian liturgy, Paul refers to psalms, hymns, and spiritual songs in liturgy. The Sanctus (from the prophet Isaiah) and the Gloria (from the angels at Bethlehem) are scriptural songs, as are other canticles (the word canticle means little song) Miriam’s song as the Red Sea enveloped the Egyptians; Mary’s song, the Magnificat; Simeon’s song among others. We sing those texts to be in keeping with how they were composed.
The Lord’s Prayer, for instance, has been set to music (first likely chant, then melodic), but it is not a song or hymn as such, and so has less of a claim to be sung than other parts of the liturgy. But adding music to prayer heightens speech: it elevates the importance of text, we pay attention more because it’s different from our everyday conversations. And so, we sing texts that aren’t usually sung at special times of the year to draw particular attention to those prayers which might otherwise be passed over as “just words.” Some Christian traditions, like the Orthodox, chant every word of every liturgy, including the scriptures, just for this purpose. We have spoken the Lord’s Prayer during Advent, Christmas, and the season after Epiphany; we will chant it during Lent and use the more melodic setting during Easter and likely into summer.
Unfortunately, ours has become a non-singing culture except at church and at baseball games (where there is often more participation at the 7th-inning stretch than even in the National Anthem), and so the division between those who consider themselves “musical” and those who don’t is more stark than in past generations. Many people have been inhibited from singing or from music in general because they were told at an early age they “can’t sing”, a real embarrassment to all of us who teach music. Singing or making music, like most things in life, is not a God-given talent but a skill, a muscle we exercise and develop or don’t.
One possible solution for people who feel too inhibited to sing or just doesn’t want to sing is to follow along with texts, reading and praying the prayers in the bulletin or reading and praying the texts from the hymns, many of which are fine poetry that even
we singers overlook. One can still participate in that communal sung prayer while not singing, though obviously not to the fullest desired extent, by being attentive to the beauty and marriage of text and music as an active listener and "pray-er."