Interpolate or not? What do you prefer?

*The purpose of the video is show that the same role can be performed in different ways - in my conception; all correct ;) - and to ask how these modifications are interesting or not. (Interpolation means basically add some extra music to some phrase or musical piece, extending it) "Interpolate or not interpolate, that is the question..." Some excerpts which show us this dilemma: sing exactly what the composer wrote and do not err or face the riscs changing the music to conquer the audience? These were their choices... *A lot of Joan and Callas examples (My fav soprano) 1.Lucia: Spargi d'amaro pianto Amelita Galli-Curci/Joan Sutherland 2.Anna Bolena: Coppia iniqua Maria Callas/Beverly Sills 3.Lucrezia: Era desso il figlio mio Montserrat Caballé/Joan Sutherland 4.Maria Stuarda: Nella pace del mesto Beverly Sills/Joan Sutherland 5.Madama Butterfly: Ancora un passo or via Renata Tebaldi/ Eleanor Steber 6.Aida: Gloria all'Egitto Birgit Nilsson/Maria Callas 7.Hoffmann: Helas, nom cœur/Adieu! Je ne veux Beverly Sills/Joan Sutherland 8.Alcina: Tornami a vagheggiar Joan Sutherland/Natalie Dessay 9.Götterdämmerung: O heilige Götter! Kirsten Flagstad/Birgit Nilsson 10.Rigoletto: Caro nome Joan Sutherland/Maria Callas 11.Die Entführung: Durch Zärtlichkeit Eidé Norena/ Lucia Popp 12.La Sonnambula: Son geloso Joan Sutherland/Maria Callas 13.La Traviata: Sempre libera Montserrat Caballé/Maria Callas 14.Mozart: Vorrei spiegarvi, o Dio Joan Sutherland/Natalie Dessay 15.Siegfried: Ewig war ich Kirsten Flagstad/Birgit Nilsson 16.Rigoletto: Ah, più non ragiono! Maria Callas/Joan Sutherland 17.Il Barbiere: Una voce poco fa Maria Callas/Mado Robin 18.Il Trovatore: Di tale amor Joan Sutherland/Maria Callas 19.Die Zauberflöte: Der Hölle Rache Mado Robin/Frieda Hempel 20.Semiramide: Dolce pensiero Maria Callas/Joan Sutherland