La Scala birthday!

The theatre was inaugurated on 3 August 1778 and was originally known as il Nuovo Regio Ducale Teatro alla Scala (lit. ’the New Royal Ducal Theatre at the Scala’ which previously was a church). The premiere performance was Antonio Salieri’s Europa riconosciuta.
Teatro dell’Opera di Roma Birthday
The Teatro dell’Opera was originally known as the Teatro Costanzi after the contractor who built it, Domenico Costanzi (1819–1898). In November 1926 the Costanzi was bought by the Rome City Council and its name changed to Teatro Reale dell’Opera. The name “Teatro Costanzi” remains officially in use, to refer to the main auditorium. Website
Gran Teatro del Liceo Birthday

El Liceu is the oldest theater in Barcelona still in use as a theater. El Liceu opened at its current address on 4 April 1847. Website