the scottish gaelic psalter was produced by the synod of argyll. by 1658, the first fifty psalms had been translated into ballad metre due to the work of dugald campbell, john stewart, and alexander mclaine. a manuscript of the final 100 psalms was produced in 1691 with the entire gaelic psalter, with revisions to the 'first fifty' being produced in 1694. the gaelic metrical psalms are used to this day in the scottish highland presbyterian churches where the practice of lining out is used, in accordance with the westminster assembly of divines directory for public worship. the corpus of tunes has shrunk over the years with only about twenty-four in general use.