In his extremely helpful book, The Writings of John Calvin, Wulfert de Greef makes a passing reference to the articles that John Calvin used for the regulation of worship after he became a minister in Geneva (January 16, 1537). This document was entitled the Articles concerning the Organization of the Church and of Worship in Geneva. I found the following to be an interesting note regarding congregational singing in Calvin’s church:
The ministers expect the singing of psalms to have a positive influence on the prayers and on the glorification of the name of God. A number of qualified children are to be selected to lead the congregation in the singing of the psalms (pg. 111).