Orfeo ed Euridice by Gluck, was written in 1762 and The Marriage of Figaro by Mozart was written in 1786. It is interesting to analyse the changes and developments from opera seria to these two examples.
During the eighteenth century, composers wrote in a style of opera called opera seria.' Opera seria had the following characteristics:
They used similar plots involving a hero and usually some sort of conflict of human passions, and these operas were often based on a story from an ancient Greek or Latin Author. The opera always consisted of three acts with alternating recitatives and arias. To show the virtuosic skill of the singer, cadenzas were used within arias. The action was created from the dialogue within the recitatives, which were accompanied by continuo and had little musical importance. There were no orchestral pieces, except for the overture and the accompaniments of the singer. It was also very common in the early part of the eighteenth century to write arias in da capo form which was a type of ternary form (ABA) which consisted of the last A section being ornamented.
Opera Reform began with the rise of the expressive style, and at the same time, there were signs of growing influence of middle-class ideas on the aristocratic standards of the early 18th century. The needs of opera were directed towards making a more natural design that had more flexibility within the structure. The content also needed to be deeper and more expressive, less laden with coloratura and more varied. Although the da capo aria was not abandoned, it was expanded and modified with more added forms. The recitatives and arias became more flexible and needed to carry on the action quickly, but realistically. The recitatives had more accompaniments with the orchestra adding more harmonic depth. Choruses became more prominent after a period of being out of fashion. There were also stricter demands of the solo singers. The two mid eighteenth century composers, Jomelli and Traetta played a big part in the reform of Italian opera in the late 18th century by influencing the French towards opera of a more international flavour.
Born in Bohemia, Gluck built a more international style of opera. He was strongly affected by the movement of the reform in the 1750s. He became court composer to the Emperor at Vienna after visits to London and studying under Samartini in Italy. After a collaboration with a poet named Raniero Calzabigi, Gluck composed two of his famous operas, `Orfeo ed Euridice' in 1762 and `Alceste' in 1767. Gluck's aims were to remove the unpopular characteristics of opera seria, as shown by his famous quote:
"To confine music to its proper function of serving the poetry for the expression and the situations of the plot"
He removed the overuse of da capo aria or the showing off desire of the singer; he also broke down the contrast of the recitative and aria and gave his opera more dramatic relevance than had been the case in opera...