Scarlatti, however, may claim a more still important innovation, the adoption of set forms: his ideas were often cast into lyrical shapes, his solos were often arias of definite mould, and above all, he deliberately adopted the _Da Capo_ Aria in the majority of his works. This _Da Capo_ Aria would be described by a student of modern form as a “Ternary” movement, in so far as its first part was entirely repeated after the performance of a contrasted middle section. That Scarlatti’s invention killed itself by its own popularity is a matter to be spoken of elsewhere: suffice it to notice that the introduction of the “_Da Capo_” Aria brought into existence a new form of opera, different to all that had gone before. [Sidenote: =England and France=] Meanwhile opera was progressing in Germany, France, and England, each school having certain distinguishing characteristics. Purcell’s work in England was unlike that of any Continental opera composer, and his melodies have a boldness, freedom, and ring about them quite their own: English music of the period was a reflex of the national character, straightforward, honest, and vigorous. At the same time, Lully in France was developing quite another side of opera, by the introduction of the ballet, a form that has been retained till within quite recent times by the French. [Sidenote: =Opera Buffa=] Handel, although the success of his operas killed, for the time being, all English-born ideas, added little or nothing to the forms of Scarlatti; he practically left opera where he found it, nor were his works as widely known on the Continent as in England. More importance may be attached to the rise, on the Continent, of a lighter form of opera, entitled “Opera Buffa,” in contradistinction to which opera proper received the title of “Opera Seria.” This delightful type had its rise in the _intermezzo_ played between the acts of a dramatic piece, and only gradually obtained a separate existence: from the early attempts of Pergolesi and others there sprung an entirely new class of work, which had great influence on the history of opera generally. Another step towards the now universally known form of opera was made when Logroscino invented the Concerted Finale, bringing several of his characters on to the stage at the same time, and giving them a simultaneous share in the music. [Sidenote: =Musical Empiricism=] Let us notice that all these improvements effected _in the music_ gradually led composers away from the true object of its use in opera, namely, that of enhancing the general effect produced; the music began to be looked upon as so important and so interesting on its own account that all dramatic considerations were allowed to lapse. Meanwhile the personalities of the singers, as opposed to that of the characters they were personating, and their vocal abilities were thrust forward to the exclusion of almost all else. [Sidenote: =Gluck=]