[4] To explain why the practice of insertion arias existed, Hilary Poriss stated: "In a world where superior vocal performance was the most highly valued economic and artistic commodity that an opera house possessed, singers inserted arias to accommodate their individual vocal strengths and ranges and to augment their roles.
[8] A highly regarded singer would not randomly choose arias to insert in whatever opera was to be performed but would make reasoned decisions based on the dramatic context and the compositional style.
[9] Poriss tells of the soprano Carolina Ungher's decisions on which aria to insert at the entrance of Elena in Donizetti's Marino Faliero.
For her performance in Florence, May 1836, she inserted the aria "Io talor piu nol rammento" from Donizetti's Sancia di Castiglia for her entrance.
In the fall of 1837, she planned to insert "Oh tu che desti ilfulmin'" from Donizetti's Pia de' Tolomei (although illness prevented her from performing this run of the opera).
Poriss argues that this indecision shows a conscious effort to select an aria that would produce the best initial vocal impression.
Yet it also shows the singer wanting to select an aria which best fit the composer's style and stayed close to the dramatic and musical shape of the opera.
Throughout much of the nineteenth and twentieth centuries, a spurious myth positing a "lost original" justified the tendency to insert music into this scene.
[15] The libretto of one of the premiere performances has a blank where the singer sings an aria, suggesting Donizetti's assertion of authorial control allowing for insertions at his discretion.
[17] A late example of the practice appears in Pauline Viardot's Cendrillon where the soprano playing the Fairy Godmother is not provided with a fixed aria in the ball scene, but instructed make her own choice of what to sing at that point.
[6] Beginning at the turn of the nineteenth century, the increasing dominance of the musical work (instead of the singer) as promoted by publishers and composers meant the eventual discouragement of insertions.
Poriss quotes from a Bellini letter describing a skirmish with Adelaide Tosi about the premiere of the revised version of Bianca e Fernando.