Psalms are sacred songs. Early psalm books might or might not contain tunes. The texts were usually designated to be of a certain meter: short, common, or long. Tunes had the same designations, allowing texts to be combined with a choice of tunes within the same meter. This way, a choir, especially one that could not read music, might sing the text to the tune they knew the best. Courtesy American Antiquarian Society
Isaac Watts wrote the text. The tune might have been composed by Aaron Williams (a Boston minister?) around 1760, or it might be an older Welsh tune.
a capella voices
Will God forever cast us off? His wrath forever smoke
Against the people of his love, His little chosen flock.
Think of the tribes so dearly bought with the Redeemer’s
Nor let Thy Zion be forgot, where once Thy glory stood.
Where once Thy churches prayed and sang Thy foes profanely rage;
Amid Thy gates their ensigns hang, and there their host engage.
And still to heighten our distress, Thy presence is withdrawn;
Thy wonted signs of pow’r and grace Thy pow’r and grace are gone.
No prophet speaks to calm our grief, but all in silence mourn; Nor know the hour of our relief, the hour of Thy return.