The Church was born singing. Paul tells the Colossians to teach one another in 'psalms and hymns and spiritual songs,' and the New Testament itself preserves canticles — Mary's Magnificat, Simeon's Nunc Dimittis, the hymn fragments embedded in the epistles.
Every age has added its voice. The Church sang the Psalms; it developed the great body of plainchant; the Reformation gave the congregation the chorale and the metrical psalm; later centuries brought the hymn traditions of Watts and the Wesleys, the spirituals, and the songs of every continent the gospel reached.
Hymnody is not decoration around theology — it is theology, carried in a form the whole congregation can hold. What the Church sings, it remembers; and what it remembers, it believes. Few things have taught the faith more widely than its songs.