In the mid-eighteenth century the music played before an opera—what came to be identified as the overture—was known as a sinfonia. There was no formal distinction between such a work and a work that, despite having the same name, was actually closer to what is now understood as a concert symphony. As composers began to more fully explore the possibilities of the latter, however, the difference between the two continued to widen. The sinfonias that served as operatic preludes were also commonly cast to be able to stand alone as independent concert works, however, and in the present case Mozart joined such a work with a reworking of other music from the opera and newly-composed material to create a "new" Sinfonia.

Following the Il ré pastore sinfonia-derived opening, the Sinfonia moves without pause into an Andantino, which similarly has its origins in music from the opera. This section is based upon the opera's opening aria, the oboe here assuming the vocal role. The remainder of the music, a transition which leads into a Presto assai, was written expressly to round out the Sinfonia. By turns lively, pastoral, and dancelike, the Sinfonia is scored for two oboes, two horns, and two trumpets, strings, and a continuo of bassoon and harpsichord.

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