As much as hymn singing has always been one of the most effective builders of Christian community, it has also always been one of the strongest dividers of Christian communities. In the early decades of the Reformation, Calvinists broke with Lutherans over several important matters, but one was existentially apparent at every gathering for worship: the singing. Lutherans sang hymns that with considerable freedom expressed their understanding of the gospel (like Luther’s “A Mighty Fortress” or “From Heaven High I Come to You”), and they often sang them with choirs, organs, and full instrumentation. Calvinists, by contrast, sang the psalms paraphrased and with minimal or no instrumental accompaniment (like the 100th Psalm, “All people that on earth do dwell,” which was prepared by William Kethe for English and Scottish exiles who had taken refuge in Calvin’s Geneva during the persecutions of England’s Catholic Mary Tudor). However natural it may now seem for Protestant hymnals to contain both Luther’s “A Mighty Fortress” and Kethe’s “Old One Hundredth,” in fact it took more than two centuries of contentious Protestant history to overcome the visceral antagonism to “non-scriptural” hymns that prevailed widely in the English-speaking world. It was even longer before organs, choirs, and instrumental accompaniment were accepted.
—Mark Noll, “Praise the Lord: Song, Culture, Divine Bounty, and Issues of Harmonization” http://www.booksandculture.com/articles/2007/novdec/9.14.html