La Scala is an opera house in Milan, inaugurated on 3 August 1778 and known initially as the Nuovo Regio Ducale Teatro alla Scala (New Royal-Ducal Theatre alla Scala). The premiere performance was Antonio Salieri's Europa riconosciuta. Most of Italy's most celebrated operatic artists, and many of the finest singers from around the world, performed in there. The theatre is rated as one of the leading opera and ballet theatres in the world and is home to the La Scala Theatre Chorus, La Scala Theatre Ballet and La Scala Theatre Orchestra. The theatre also has an associate school, known as the La Scala Theatre Academy, offering professional training in music, dance, stage craft and stage management. According to the tradition, La Scala's season opens on 7 December, Saint Ambrose's Day, the feast day of Milan's patron saint and all performances must end before midnight, and long operas start earlier in the evening when necessary.