What a many-colored career that was which began amidst the pastoral solitudes of Bethlehem, and ended in the chamber where the dying ears heard the blare of the trumpets that announced the accession of Bathsheba's son! None of the great men of scripture pass through a course of so many changes as David; none of them touched human life at so many points; none of them were so tempered and polished by swift alternation of heat and cold, by such heavy blows and the friction of such rapid revolutions. These quick transitions of fortune, and this wide experience, are the many-colored threads from which the rich web of his psalms is woven.
And while his life is singularly varied, his character is also singularly full and versatile. In this respect, too, he is most unlike the other leading figures of Old Testament history. Contrast him, for example, with the stern majesty of Moses or the unvarying tone in the gaunt strength of Elijah. These and the other mighty men in Israel are like the ruder instruments of music - the trumpet of Sinai, with its one prolonged note. David is like his own harp of many chords, through which the breath of God murmured, drawing forth wailing and rejoicing, the clear ring of triumphant trust, the low plaint of penitence, the blended harmonies of all devout emotions.
(Adapted from the introduction)