Warren Steel pointed out to me the following interesting piece about "continuous singing".
It is often objected that the reading of the line interrupts the singing and "spoils the music." Well, the singing is indeed necessarily and temporarily interrupted; but edification is thereby promoted; and suppose the music marred, or even "spoiled," what then? Is the chief end now to worship the music? This is idolatry, however refined. It is, I believe, the uniform testimony of those who from this country visit the churches of the reformation in the British Isles, that the united voices of the worshippers in the great congregation there, where all "sing praises with understanding;" far excel all the choirs, solos or quartets in American churches.
Again, it is said that "all our people ought to be so well acquainted with the Psalms as to be able to sing them without a book." Suppose this to be the case with adults; it is not to be expected of children, whom God commands, as we have shown, to concur in this part of his service. But it is proper to add, that perhaps those who bring this objection, may be found as deficient in this part of Christian acquisition as some of their brethren. Besides, there is a vast difference between committing the Psalms to memory, and "getting them by heart." Satan himself excels in the former as we see (Ps. 91:11, Matt. 4:6): but the latter is beyond his power. I have known a young man who excelled all the members in a fellowship meeting, in committing to memory all the Psalms and both Catechisms! He married a Papist, and went to mass! His memory was not at fault; but "his heart was not right with God." "Five words" outweighed with Paul, "ten thousand words in an unknown tongue," or what is equivalent, absolute silence, (1 Cor. 14:16).
David Steele in Continuous Singing in the Ordinary Public Worship of God, Considered in the Light of Scripture and ...