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. 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. History The singing of psalms was included in the synagogue service at the time of Jesus. Early Christians appropriated this tradition, as well as many other elements of synagogue worship. The whole congregation may have sung, or there may have been a cantor who would sing each verse with the congregation responding by singing "Hallelujah." Such a pattern appears outside the psalms; each song in the obscure early Christian poetry collection known as the Odes of Solomon concludes with a "Hallelujah", indicating a similar liturgical purpose for its ancient users. The Psalms of David formed the core of liturgical music for the early church, to which other songs from the Old and New Testaments (canticles) were added. In addition, early Christians wrote original compositions for singing in worship alongside biblical texts. Soon after the New Testament period, psalmody took a preferred position in the worship of the church. There was some hymn-writing in Eastern churches, but in the West psalms and canticles were used almost exclusively until the time of Ambrose of Milan at the end of the fourth century. Even then, the psalms were never completely replaced by original hymns. During the Protestant Reformation, new church music was written in order to revive the practice of congregational singing, which had been replaced by the singing of monastic choirs in Latin. Martin Luther and leaders of the Reformed wing of the Reformation in Strasbourg, Constance, and elsewhere wrote music for psalm texts as well as original hymns, but John Calvin in Geneva used biblical psalms almost exclusively in the Genevan