The situation in France was somewhat different. French opera, as seen in the tragédies lyriques of Lully, was essentially a court spectacle, predominantly on legendary or mythological themes, and in five acts, with big choral and ceremonial scenes reflecting the magnificence and social order of the age of Louis XIV. France and Germany both imported Italian opera in the later 17th century, and there were attempts at German-language opera, especially at Hamburg, where an opera house had opened in 1678, Keiser was the leading figure and Handel wrote his first operas. In England, French influence was at first dominant in the ‘semi-opera’ with spoken dialogue; all-sung English operas, of which Purcell's Dido and Aeneas is the outstanding 17th-century example, were to be a rarity until well after 1900.

In the early 18th century there was a reaction in Italy against the alleged extravagance, over-elaboration and confusions of the 17th-century libretto; this was initiated by Zeno and completed after 1720 by Metastasio, whose opera seria librettos were set by numerous composers throughout the 18th century, including Vinci, Leo, Porpora, Hasse, Jommelli, Paisiello and Cimarosa. (Handel, whose mature operas were written for London and lie off the mainstream of the Italian tradition, set only three of them, adjusted to his requirements.) Metastasio's librettos serve as a model of the prevailing rationalist philosophy, the action moving through conflicts and misunderstandings to an inevitable lieto fine (happy ending), in which merit receives its due reward, often brought about through an act of renunciation by a benevolent despot. The music is equally orderly, largely an alternation of recitatives (in which the action takes place) and arias (in which the characters give vent to their emotional states). It is, however, important to realize that in 18th-century opera, particularly as given in public opera houses, the composer was not the dominant figure he was to become: operas were usually put together by house composers and poets, often drawing on several composers music, old and new, to suit the available singers, who (then as now) were the chief draw - above all the castratos and the sopranos.

As the century went on, the structure of opera seria was again challenged, this time from below. Lighter forms of opera, such as opera buffa in Italy, opéra comique or comédie mêlée d′ariettes in France, ballad opera or comic opera in England and Singspiel in Germany, came from humble beginnings to flourish alongside opera seria and even to penetrate its substance. Serious opera began to change in the direction of freer choice and more imaginative treatment of subject matter, reflected in the music by modifications of the strict da capo and the rise of new aria forms, greater use of accompanied recitatives and of the chorus, and in the end a virtual fusion of the formerly distinct French and Italian characteristics. The ‘reforms’ of Traetta, Jommelli and especially Gluck (Orfeo ed Euridice, 1762) were stages in this process; the final stage is best represented by the operas of Mozart from Idomeneo (1781), including his three with Da Ponte with their many ensembles (including extended act finales, following the Venetian reforms of the poet Goldoni and the composer Galuppi) which bring a new emotional weight to comic opera. Two-act form came to be preferred, especially in comic opera, at this period.

By the early 19th century, even ‘serious’ opera had moved from its earlier aristocratic milieu into the great public theatres with their mass audiences. One manifestation of this was the popularity of ‘rescue’ operas, of which Beethoven's Fidelio (1805) is the best known. Popular audiences were undoubtedly an influential factor in the growth of French grand opera, with its emotion-charged plots, colourful orchestration and massive choral numbers; this is seen at its most successful in the collaboration between the librettist Scribe and the composer Meyerbeer. Nature and the supernatural entered into the substance of the drama, particularly in Germany with Weber, Marschner and others.

While Italian serious opera as cultivated by Rossini, Donizetti and Verdi remained relatively conservative, there was a move towards greater musical continuity during the 19th century. The rigid separation of recitative and aria was gradually broken down, and virtually eliminated in the Wagnerian music drama, with its ‘endless melody’ and elaborate system of leitmotifs, and (in a different way) in the final works of Verdi and the verismo operas of his Italian successors, above all Puccini.