Though born in Cremona, where he also studied at the University of Cremona, Monteverdi spent most of his career at the court of Vincenzo I of Gonzaga in Mantua. Along with Monteverdi, Vincenzo also employed the painter Peter Paul Rubens.
We learn from Tomlinson's monograph on Monteverdi that "The Mantuan style of 1595 - 1600 is above all a homophonic language of flexible, text-inspired declamatory rhythms ... Imitative textures are infrequent..." Also: "The Ferrarese style, in contrast favors mercurial, single-subject imitation at quick rhythmic intervals." He goes on to point out the differences in harmonic structure: the Ferrarese style is more undirected and has a wayward sound to modern ears. In the Mantuan style the bassline is more distinct and freer to support a harmonic foundation.
The very unusual composer Carlo Gesualdo was himself a nobleman, born in Venosa, then part of the Kingdom of Naples. On the death of his father he became Prince of Venosa. He was dedicated to music his whole life and took up residence in Ferrara because of its role as a center of musical activity. After a few years he returned to his castle at Gesualdo bringing with him a number of musicians and singers from Ferrara. Gesualdo was known for a style using extreme chromaticism and some of his madrigals seem to have influenced Monteverdi who knew his work.
Let's listen to a couple of pieces from Gesualdo's Fourth Book of Madrigals. First, "Sparge la morte" performed by the Ensemble "Basiliensis":
Next, "Ecco morirò dunque" performed by the Monteverdi Choir conducted by John Eliot Gardiner:
Working alongside Monterverdi in Mantua was Benedetto Pallavicino, here are the Ensemble Basilensis with his "Deh, dolce anima mia":
So I hope that gives you a bit of musical context of late 16th century northern Italy, a place that was the birthplace of a great deal of great music.