About the work
Demetrio is an opera seria in three acts by Josef Mysliveček, based on Pietro Metastasio's popular libretto first performed in 1731. The premiere took place on 24 May 1773 at the newly built Teatro Nuovo in Pavia — Mysliveček had the honour of opening the city's new theatre with his work.
Plot
Cleonice, queen of Syria, and the young Alceste love each other, though political constraints and difference of rank stand in the way of their union. Only when Alceste is revealed to be Demetrio, the rightful king of Syria believed dead, are the entanglements of succession and love resolved together.
Cultural significance
The showpiece aria "Agitata in tanti affanni," written for soprano Lucrezia Aguiari, became especially famous and soon circulated in numerous contemporary aria anthologies thanks to its extreme high tessitura. Musically, Demetrio also marks the end of an early phase in Mysliveček's output still dominated by extended da capo arias, before he increasingly turned to forms based on sonata structure.