In the musical world that Donizetti entered as an opera composer in 1817, new works were designed to produce, hopefully, an immediate success. The ready assimilability of opera in Italy at this time was assured by the composer's general adherence to a number of conventions of musical forms and procedures; and it follows that a work's success was measured by the composer's skill, or want of it, in filling these forms with music that struck an audience as fresh and dramatically appropriate, rather than as novel or innovative. During the years of Donizetti's activity he gained greater freedom and adroitness in his treatment of these units of the basic framework, but he never came to the point of breaking away from them completely. Indeed, his fecundity, and that of some of his contemporaries, is unthinkable without this undergirding of traditional procedures. The measure of Donizetti's originality is to be taken from his adaptiveness in handling these conventions and the skillful ways he learned of modifying them.

The conventions applying to preludes and overtures afford a logical starting-point. There is no opera by Donizetti that does not start without some music, however brief, to precede the curtain's rise. Preludes and overtures are distinguishable on structural terms. A prelude is short, ranging from five measures (Elvida) to fifty-two (La zingara and Dom Sébastien).