Die Schuldigkeit des ersten Gebots, K. 35, is a sacred musical play composed by Wolfgang Amadeus Mozart in 1767 when he was 11 years old. It is Mozart's first opera or, more specifically, sacred drama, as is suggested by the name. Wikipedia
Composers: Wolfgang Amadeus Mozart and Michael Haydn
Librettist: Ignatz Anton von Weiser
First performance: March 12, 1767, Salzburg Residence, Salzburg, Austria
Composed: 1767