The sonata's greatest companion-piece, the symphony, also came into existence through the efforts of Italian musicians. The word sinfonia first appears with a very uncertain meaning. In general, it was used to mark the distinction between vocal and instrumental movements in cantatas, in sacred music, and, later, in opera. At the beginning of the seventeenth century we find the word used for the first time in large vocal works, and applied to interludes, ritornelle and preludes. This became the general custom when opera was introduced, and the short instrumental prelude was always entitled symphony. This last species of composition is, indeed, to be considered as the origin of our classical symphonic form. Not all the early operas had instrumental introductions, although Jacopo Peri himself made use of them. In his "Eurydice" there is a symphony for three flutes! Monteverde considerably enlarged the form, but seemed to find in it no characteristic expression of his ideas. At that time the form consisted of three parts, a slow movement, a quicker movement, and again a slow movement. This form of the symphony had really no artistic connection with the opera which followed, but was only a musical piece to inform the hearers that the performance was about to begin. Later, however, came works with more marked and pertinent character, which bore the names, overture and toccata. Finally, through the introduction of ballet-melodies, the symphony became of a livelier nature. At the same time, the word symphony gained more significance, and, as its inner construction kept pace with the modest beginning of the sonata form, it became visibly more artistic, more musical and of a more clearly-defined form. We early come in contact, however, with a different kind of sinfonia, invented by an Italian who had become identified with the French school. This form corresponds more nearly to the overture of the present day. Jean Baptiste Lully first used this form. It consisted of a slow, dignified movement, followed by one of light, French style, and closing with a slow movement, which, however, was of less serious character than the first.
The next manifestation of the overture form resembled still more closely our symphony of to-day, in that it began and ended with quick movements. The middle movement was an andante. It is difficult to decide which of the Italian composers first used this form. The details of the development of the separate movements were, in comparison with earlier works of similar character, more careful and more strict. Evidences of the purely musical interest in the perfection of form thus manifested themselves, and the artistic arrangement of ideas made the work much more comprehensible to the public. From its earliest day, this species of composition has borne a clearly defined resemblance to our modern orchestral works, and, under the formative influence of the multitude of composers who used it, the sinfonia italiana made rapid progress towards perfection. By the beginning of the eighteenth century there was that unanimity of ideas among composers which indicates that a musical form exists as an independent thing. We find perhaps the best specimens of these "symphonies" in the overtures to "Catone in Utica" by Lionardo da Vinci and to "Il Mondo alla Riversa" by Galuppi, the latter of which was given one year before Joseph Haydn wrote his first symphony. Another excellent specimen is the overture to the "Bidone" of Piccinni; and, indeed, we find the form in use by Mozart in his first attempt at opera, "La Finta Semplice."