Exclusive psalmody is the practice of singing only the biblical Psalms in congregational singing as worship. Today it is practised by several Protestant, especially Reformed denominations. Hymns besides the Psalms have been composed by Christians since the earliest days of the church, but psalms were preferred by the early church and used almost exclusively until the end of the fourth century.^: 40 During the Protestant Reformation, Martin Luther and many other reformers, including those associated with the Reformed tradition, used hymns as well as psalms, but John Calvin preferred the Psalms and they were the only music allowed for worship in Geneva. This became the norm for the next 200 years of Reformed worship. Hymnody became acceptable again for the Reformed in the middle of the nineteenth century, though several denominations, notably the Reformed Presbyterians, continue the practice of exclusive psalmody.