Giuseppe Piermarini's grand 2800-seat theatre was inaugurated in 1778, replacing the previous theatre, which burnt down in a fire after a carnival gala. Costs were covered by the sale of palchi (private boxes), of which there are six gilt-and-crimson tiers. When rehearsals are not in session you can stand in boxes 13, 15 and 18 for a glimpse of one of the largest stages in Europe. In the theatre's museum, harlequin costumes hint at centuries of Milanese musical drama.
Drama, when it's not coming off the stage, is often generated in the two loggione (galleries) that sit above the private boxes. Occupants of these seats, the loggionisti, are the opera's fiercest critics. They famously booed tenor Roberto Alagna off the stage in 2006, who was hurriedly replaced by his understudy Palombi who, lacking the time to change into full costume, appeared in his T-shirt and jeans.