Shaped like a compressed oval, the interior of the city's opera house is breathtakingly ornate compared with its sombre façade, and one of the most technologically advanced in Europe. Productions are impressive, with complicated revolving sets and attention to detail in costume and props, and range in style from the traditional lyrical repertoire to the latest avant-garde trends. Projection screens at either side of the stage show the full-stage action, though this doesn't quite compensate for the lack of vision at the far ends of the top galleries (the 'tribunas' and part of the 'anfiteatro'). There is also a screen above the stage showing Spanish surtitles for non-Spanish operas. The acoustics are so good that sound quality is practically the same everywhere in the hall.
There are daily guided visits that tell you all about the building's structure, the decoration of public spaces and how an opera house works (you'll be able to explore everything from the main dressing room to the auditoriums). If you're a professional or student, or simply interested in the technical side of things, there are also daily artistic and technical visits that last around an hour and a quarter. Night owls and those interested in finding out what happens after the curtain falls can also take a night tour.
Performances usually begin at 7pm and 8pm, or 6pm on Sundays, with ballet and family opera matinées at noon. The date tickets go on sale is announced on the venue website; there is a limit of four per person and they tend to sell out quite quickly. With the cheapest tickets, for rows F and G, vision is seriously reduced; check the website for a detailed plan.