Bastien and Bastienna is Mozart’s earliest musical comedy and most likely was first performed on December 7th, 1768, at the summer house of Dr Franz Mesmer’s mansion. It is in one act.
Leopold Mozart was relentlessly on the lookout for commissions for his 12-year old talented son. But times were hard. The second journey to Vienna was a succession of disappointments, with no commissions in sight. Finally, the family was excited to receive a commission from a music aficionado – the Viennese doctor Franz Anton Mesmer. He gave Mozart the text for a musical comedy in German: “Bastien and Bastienna”.
According to contemporary custom, it was a genre that was known as Opéra comique, or according to Mozart’s father an “Operetta”. Even at this age Mozart tinkered with the story – with the help of Johann Andreas Schachtner, a friend of his father – until he liked the libretto and felt ready to start the composition.
He immensely enjoyed his work, as is evident in the simple but spirited melodies.
The plot - the shepherdess Bastienna has a problem ...
The cunning Phyllis is meddling with Bastienna’s amorous relationship with Bastien. The clairvoyant Colas advises Bastienna not to give anything away despite her jealousy.
Bastien also seeks the advice of the clairvoyant to tell him of his marriage plans with Bastienna. Colas makes him believe that there is somebody else in Bastienna’s life. Bastien rages with jealousy.
Bastienna – following the clairvoyant’s counsel – does not react. Bastien subsequently threatens to commit suicide and moves Bastienna’s heart. The lovers are reconciled.
Description from Mozart.com