This is such a piece of joy – the bass line is either a C major scale, or I, Ic, IV, V, with a repetitive solo-chorus, or imitative instrument section.
Scored for SSATTB (with the Alto getting hardly anything to do), violins and continuo, it’s a setting of Psalm 112 – the later part of the text includes the gnashing of teeth, which Monteverdi depicts with running scales and ornaments.
This was composed for the 1640 publication Selva morale e spirituale which includes madrigals, motets, and a mass setting. It is the most important publication of Monteverdi’s after the Vespers of 1610.