Compared to the lively and irregular metres of the Genevan Psalter, the Scottish Psalter's ubiquitous common metre texts can seem monotonous in the extreme. However, the Rev David Silversides makes a legitimate point in defence of the latter in his piece on The Development of the Scottish Psalter:
It is a lovely biblical thought, is it not, that the Psalmody of the people of God should be such that as many as possible, even those of limited musical ability, can seek to join in? Yes, we should make our Psalmody as beautiful as possible, but without causing one of the saints of God to be left unable to attempt to sing because of its complexity. It should never become so elaborate that we end up with those who are musically skilled as the only ones who can really sing. At the Reformation, there was a deliberate reversal of Rome's practice of having the professional singers perform to a silent congregation. Our Reformers purposely sought to have the Psalms sung by the whole congregation of the people of God. John Calvin in Geneva resisted anything too complex in the singing of Psalms in order to ensure that the whole congregation could join in the praise of God.
Did the Scottish Psalter achieve this aim of simplicity? Well, let us ask the question: How many tunes do you need to know to be able to sing the whole Scottish Psalter through? The answer of course is one. It may not be desirable, but if you can manage one tune, you can sing every verse in the Book of Psalms from the Scottish Psalter. Where there is only one version of a particular Psalm, it is always in common metre (i.e. the number of syllables in the four lines respectively is 8:6:8:6). If there are two versions of a particular Psalm, one of them is always in common metre. This means that if you can remember the tune that our precentor used in singing Psalm 95 this evening, then you could sing every Psalm to that tune if you use the Scottish Psalter. Now that is simplicity if ever it existed.