“2. The Covenanter Church believes that it is sinful to sing uninspired hymns in the worship of God. The Presbyterian, Methodist and many other denominations do not so believe. We are convinced that we can give a valid Scriptural proof for our position on this matter. To us it is not a matter of indifference, but a very important matter indeed. How Almighty God is to be worshipped is no trifle to be decided according to human pleasure and preference. But the advocate of open communion asks, in effect, that the position of the Presbyterian and Methodist Churches be made the rule that shall govern the practice of the Covenanter Church concerning admission to the Lord’s Supper.”
J.G. Vos discussing admittance to the Lord’s table.
The whole work can be found here
“2. They (the Nature of the Distinctive Principles of our Church) are based on the authority of Scripture. (First Term of Communion; Confession of Faith, I.6, first sentence). It is useless to discuss these principles with any person who does not accept the supreme authority of Holy Scripture for faith and life. That politics, religious worship, social affiliations, etc., must be controlled by the authority of Scripture, not by human preference or customs, is a new idea to many people. Many people in various denominations today have no really vital conviction of the authority of Scripture. They are not in the habit of examining problems in the light of Scripture. For example, there are no doubt millions of church members who regularly use uninspired hymns and instrumental music in worship, who have never even thought of asking the question “Are these practices Scriptural?” Most people just act according to custom without independent thinking and without asking any questions.”
a selection from The Nature of the Distinctive Principles of our Church, J.G. Vos
posted recently at the Old Light Covenanter blog here