Cabaletta

Cabaletta is a two-part musical form particularly favored for arias in 19th century Italian opera in the bel canto era until about the 1860s during which it was one of the era's most important elements. More properly, a cabaletta is a more animated section following the songlike cantabile. It often introduces a complication or intensification of emotion in the plot. Some sources suggest that the word derives from the Italian cobola (couplet).