From James Hastings Nichols, Corporate Worship in the Reformed Tradition, pp. 58, 59.

The Huguenots quite caught Calvin’s concept of congregational psalmody.  It became their hallmark, in homes, in corporate worship, or on the battlefield.  The French Discipline required all to own and bring their liturgical psalters, and to share in the singing.  The synods took the sung prayers very seriously.  Figeac censured the practice of lining out (1579).  Rochelle censured those who did not sing in service (1581).  Synods o fthe early seventeenth century required the use of the whole psalm and ruled against the use of one or two stanzas only.  They were not strictly held to the psalms.  Beza had introduced some hymns and these were authorized by the synod of Montpellier (1598).  However, in general, little but psalms were sung in the sixteenth- and seventeenth-century French Reformed Church.