Isaac Watts (1674 – 1748) was an English Christian hymnwriter, theologian and logician. A prolific and popular hymn writer, his work was part of evangelization. He was recognized as the "Father of English Hymnody", credited with some 750 hymns. Many of his hymns remain in use today and have been translated into numerous languages.
Sacred music scholar Stephen Marini (2003) describes the ways in which Watts contributed to English hymnody. Notably, Watts led by including new poetry for "original songs of Christian experience" to be used in worship. The older tradition was based on the poetry of the Bible, notably the Psalms. Watts' introduction of extra-Biblical poetry opened up a new era of Protestant hymnody as other poets followed in his path.
Watts also introduced a new way of rendering the Psalms in verse for church services. The Psalms were originally written in Biblical Hebrew within Judaism. Later, they were adopted into Christianity as part of the Old Testament. Watts proposed that the metrical translations of the Psalms as sung by Protestant Christians should give them a specifically Christian perspective.
http://en.wikipedia.org/wiki/Isaac_Watts
New ed. / the selection enl., and the indexes greatly improved by Samuel M. Worcester
The Psalms of David, imitated in the language of the New Testament : p. [51]-289
Includes indexes
Without music