“...and to us David’s Psalms seem plainly intended by those terms of Psalms and Hymns and Spiritual Songs, which the Apostle useth, Ephes. 5.19, Col. 3.16. But then ’tis meet that these Divine composures should be represented to us in a fit translation, lest we want David, in David; while his holy ecstasies are delivered in a flat and bald expression. The translation which is now put into thy hands cometh nearest to the Original of any that we have seen, and runneth with such a fluent sweetness, that we thought fit to recommend it to thy Christian acceptance; Some of us having used it already, with great comfort and satisfaction.”

- Subscribed by Thomas Manton, Henry Langley, John Owen, William Jenkyn, James Innes, Thomas Watson, Thomas Lye, Matthew Poole, John Milward, John Chester, George Cokayn, Matthew Meade, Robert Francklin, Thomas Dooelittle, Thomas Vincent, Nathanael Vincent, John Ryther, William Tomson, Nicolas Blakie, Charles Morton, Edmund Calamy, William Carslake, James Janeway, John Hickes, John Baker, Richard Mayo in the “Letter to the Reader” in an edition of the 1650 Psalter, for the Company of Stationers, London, 1673 as cited at http://www.reformation-scotland.org.uk/articles/development-of-scottish-psalter.php (emphases added).

This 1650 Scottish Psalter is FREE at Reformation Worship, the Regulative Principle of Worship (RPW), Iconoclasm, etc., and is also known as The Psalms of David in Metre (being the Scottish Metrical Psalter, first authorized by the Westminster Divines and then also by the General Assembly of the Church of Scotland [in 1650], with notes by John Brown of Haddington.)

Many more free resources on Psalm Singing are at Reformation Worship, the Regulative Principle of Worship (RPW), Iconoclasm, etc.