The current edifice is the second theater on the site. A fire destroyed the first, the ancient Teatro Ducale, on February 25, 1776, after a carnival gala. A group of ninety wealthy Milanese, who owned palchi (private boxes) in the theater, wrote to Archduke Ferdinand I of Austria asking for a new theater and a provisional one to be used while completing the new one.
The new theatre was be built on the former location of the church of Santa Maria alla Scala, from which the theatre gets its name. The church was deconsecrated and demolished, and over a period of two years the theater was completed by Pietro Marliani, Pietro Nosetti and Antonio and Giuseppe Fe. The theater was inaugurated on August 3, 1778, under the name Nuovo Regio Ducal Teatro alla Scala with Salieri's L'Europa riconosciuta.
Building expenses were covered by the sale of palchi, which were lavishly decorated by their owners, impressing such observers as Stendhal. La Scala (as it was soon became to known) soon became the preeminent meeting place for noble and wealthy Milanese people. In the tradition of the times, the platea (the main floor) had no chairs and spectators watched the shows standing up. The orchestra was in full sight, as the golfo mistico (orchestra pit) had not yet been built.
Above the boxes, La Scala has always had a gallery where the less wealthy can watch the performances. It is called the loggione. The loggione is typically crowded with the most critical opera aficionados, who can be ecstatic or merciless towards singers' perceived successes or failures. La Scala's loggione is considered a baptism of fire in the opera world, and fiascos are long remembered. (The famed tenor Carlos Bergonzi, back on stage after many years, wasn't forgiven for a bad start to his Aida and suffered merciless fischi — whistles, which in Italy signify contempt).
As with most of the theaters at that time, La Scala was also a casino, with gamblers sitting in the foyer.
La Scala was originally illuminated with eighty-four oil lamps mounted on the palcoscenico and another thousand in the rest of theater. To prevent the risks of fire, several rooms were filled with hundreds of water buckets. In time, oil lamps were replaced by gas lamps, these in turn were replaced by electric lights in 1883.
The original structure was renovated in 1907, when it was given its current layout. In 1943, during WWII, La Scala was severely damaged by bombing. It was rebuilt and reopened on May 11, 1946, with a memorable concert conducted by Arturo Toscanini.
La Scala hosted the prima (first production) of many famous operas, and had a special relationship with Giuseppe Verdi. For several years, however, Verdi did not allow his work to be played here, as some of his music had been modified (he said "corrupted") by the orchestra.
It now hosts a museum (accessible from the foyer) with an extraordinary collection of paintings, drafts, statues, costumes, and other documents regarding opera.
La Scala's season traditionally opens on December 7, Saint Ambrose's Day, Milan's patron saint. All performances must end before midnight; long operas start earlier in the evening if need be. Ticketholders are not allowed to enter after the performance has begun (No exceptions are made, as Richard Burton once discovered.)
The theater is currently closed for restoration.