The reform of church life in Geneva included not simply doctrine but also worship and church polity. In worship, the biggest change was the elimination of images, colorful vestments, choirs and organs, the pageantry of the Mass and a stress upon Scripture, particularly in the form of sermons that carefully explained sections of the Bible. The stress on the Word of God was particularly evident in Calvin’s insistence as early as 1537 that congregational singing in Geneva use the Old Testament Psalter. Not only did Reformed Protestant worship involve the laity in ways dramatically different from the medieval church, but the creation of the Geneva Psalter, the production of which involved metrical translations from Clement Marot and tunes composed by Louis Bourgeois, established psalm-singing as the pattern for Protestant worship outside Lutheran and Anabaptist circles that would prevail for at least three centuries (in some places five).
Taken from Calvinism: A History by Hart.