Well, let's kick-in with the rise of the Italian solo singer that was to give birth to the form of opera...  Ferrara was the home-town of soprano diva (and lutenist) Anna Guarini 1563-98.  She was one of the first "high sopranos" on record, and both Agostini and Monteverdi wrote for her...  the poet Tasso (whose poetry Monteverdi would later use as a source for librettos) celebrated her artistry in verse.  With two other female singers they appear to have formed an early example of the Baroque Babes, the Concerto di Donne, and they toured Italy as a trio.

Having served the d'Este family, under whose fabulously wealthy patronage she became widely famous, her family appear to have arranged a marriage for her - evidently against her will - to a much older and extremely stern aristocrat, Count Trotti.  Rumours flew of an affair with one of Trotti's own Personal Guard, but whilst the Duke d'Este remained alive and her protector, Anna was safe.  The instant that the Duke died, Trotti smashed down her bedroom door (with the assistance of her own brother), and hacked her to pieces with a meat-cleaver.

Amazingly the Duke's successor gave Trotti a full pardon and elevated him in the aristocracy with the gift of further lands.  The appointment of Pope Clement in the following year effectively wound-up this brief flowering of musical experimentation in Ferrara, and the Concerto di Donne was no more.

One would like to imagine that Guarini's last words to her husband included wishing him a journey to Hell on a bicycle, but other than that I'm stuck for a Continuity Link with the topic 
 

Frescobaldi?

They were indeed.  John Eliot Gardner's recording of Cosi was live in the opera house there.

There's someone who inspired a lot of opera scenarios (and at least one beast in Harry Potter) who lived there, although a bit earlier than the development of opera.

And some famous musical fountains, although not in Ferrara itself.

Lucrezia  Borgia?  I hadn't though of her.  Thank you.  I was sure this question would come up with some matters I didn't think of.

I was thinking of a poet in Ferrara whose major work provided subject matter for a number of well known Handel operas, as well no doubt other composers.

Spot on Ruth.

According to the biog in the front of the Penguin Orlando Furioso, Ariosto was the son of an official of the Ferrarese court and spent all his adult life in the service of the Ferrarese ducal family.

On a previous visit, I seem to remember finding a Casa Ariosto in the back streets.

And the musical fountains?

And, not musical, but very tasteful, a Visconti film and its novel?

Thanks again Ruth.

I tend to muddle up operas based on Ariosto and operas based on Tasso.

Nice to catch a glimpse of you, Don! (And your pal there.)