Reading back over the thread provided clarity. The songs for the worship of the OT church were inspired prophecies. There is no continuing office of prophet; no more setting (i.e. the temple) in which that office would continue in the writing of inspired psalms ; and no command from God for the writing of uninspired songs for worship. As covenant theologians, we ought to be looking for what was abrogated in worship (the ceremonial) vs. what continued on into the new covenant. Hymns, whether for public worship or other use, were written pretty early on in the early church. Other errors also crept in early, and continued to creep in. But again, there had been no command from God for the further writing of any songs for the worship of the church.