Almost no hint is ever offered to the eager listener of the extraordinary wealth of music that lies behind the few famous names representing opera in the nineteenth century. Nor of its enormous quality. You would never guess that Giovanni Pacini  was once as famous as Bellini (and lasted much longer), that Simon Mayr contested first place with Rossini, or that Errico Petrella's operas were as popular and had a reception as tumultuous as those of Verdi in the 1860's. The huge audiences that flocked to hear their music have long been discounted or ignored by received opinion.
The same factor applies to all of Europe.  Opera reached its peak in the nineteenth century in terms of popular culture, the Opera House offered a cosmic pattern for the whole of society with the rank and file ranged noisily with the Gods painted on the ceiling and making its presence felt.
The variety and sheer number of neglected composers of the nineteenth century has never been surpassed -  not only in Italy, France and Germany - but almost everywhere else too. There are three submerged generations of nineteenth century composers awaiting revival.
The operas of the  seventeenth and eighteenth centuries are eagerly advocated today,  the re-emergence of the nineteenth century in all its fervour, drama, and lyrical extravagance is long overdue.