This duet is from Mozart's "Don Giovanni"
Usually this would be a major aria / duet etc or when a particularly loved performer makes their entrance.
An opera curtain call is not an encore, it is an opportunity for the cast to present themselves -- usually in character -- at the front of the stage, so that the audience can show its appreciation for the performance. An encore would include music -- a repeat of a section, aria, duet, or other music from the story.
On a purely subjective basis - In Puccini's La boheme - the conclusion of act 1 two solos and a duet which I look upon as a duet overall. When Rodolfo and Mimi declare their love. First he sings to her 'Che gelida manina' her tiny hand is frozen, she then replies with 'Sì, mi chiamano Mimì' she is called Mimi and finally they go out singing 'O soave fanciulla' the duet opens [roughly] 'Oh lovely girl, oh sweet face bathed in the soft moonlight'. Also - Carmen act 4 C'est toi? C'est moi, the love duet from Madame Butterfly and act 1 love duet from la traviata.
There are "tons" of great operatic duets sung by women, but one of my personal favorites is The Flower Duet from Léo Delibes' Lakmé. A couple of other great ones are Canzonetta Sull'aria from the Marriage of Figaro by Mozart and Belle Nuit O Nuit D'Amour from The Tales of Hoffman by Offenbach. Oh...Oh...but wait, we can't forget the beautiful Flower Duet from Puccini's Madama Butterfly.Edit:*La Pesca - duet for soprano and mezzo soprano by Rossini.& I found a link with a list: http://www.opera-arias.com/duets/soprano-soprano/ Also, not all aria duets were in actual operas. https://en.wikipedia.org/wiki/List_of_songs_and_arias_of_Johann_Sebastian_Bach
The excerpt used in this commercial is taken from Mascagni's opera, Cavalleria Rusticana. The duet is between Santuzza and Turiddu - the opera is only about 1 hr long and this duet is about 12min long - this is from the "Turiddu, ascolta" section of the duet. I've sung the soprano part before and it still took me a while to figure it out!!
'Flower Duet' by Léo Delibes, from the opera 'Lakmé.'
In the international virtual boutique i heard "the flower duet"
Viens Mallika - From the Flower Duet Opera
the flower duet from lakme , leo delibes...
"Flower Duet" from Delibes' opera Lakme
Opera is Lakme by Delibes. Song is The Flower Duet.
This duet is from Mozart's "Don Giovanni"
Usually this would be a major aria / duet etc or when a particularly loved performer makes their entrance.
Au Fond Du Temple Saint, from Bizet's Les Pecheurs De Perles, is a duet in which two men swear to be friends until death.
The flower duet from Lakme
Is the Flower Duet from the Opera Lakme, by Leo Delibes