The past thirty years have seen frantic attempts by architects to escape the domination of the "shoe-box" concert hall. Rather than struggle with the inescapable acoustic superiority of this traditional shape, the Casa da Musica attempts to reinvigorate the traditional concert hall in another way: by redefining the relationship between the hallowed interior and the general public outside. The Casa da Musica, the new home of the National Orchestra of Porto, stands on a new public square in the historic Rotunda da Boavista. It has a distinctive faceted form, made of white concrete, which remains solid and believable in an age of too many icons. Inside, the elevated 1,300-seat (shoe box-shaped) Grand Auditorium has corrugated glass facades at either end that open the hall to the city and offer Porto itself as a dramatic backdrop for performances. Casa da Musica reveals its contents without being didactic; at the same time, it casts the city in a new light.
Locating the Casa da Musica was key in the development of OMA's thinking; we chose not to build the new concert hall in the ring of old buildings defining the Rotunda but to create a solitary building standing on a travertine-paved plateau in front of the Rotunda's park, neighbouring a working class area. With this concept, issues of symbolism, visibility, and access were resolved in one gesture.
As well as the Grand Auditorium, conceived as a simple mass hollowed out end-to-end from the solid form of the building, the Casa da Musica also contains a smaller, more flexible performance space with no fixed seating, ten rehearsal rooms, recording studios, an educational area, a restaurant, terrace, bars, a VIP room, administration areas, and an underground car park for 600 vehicles.
Innovative use of materials and colour throughout was another imperative: as well as the unique curtain-like glass walls at either end of the Grand Auditorium, the walls are clad in plywood with enlarged wood patterns embossed in gold, giving a dramatic jolt in perspective; the VIP area has hand-painted tiles picturing a traditional pastoral scene, while the roof terrace is patterned with geometric black and white tiles; floors in public areas are sometimes paved in aluminium.
There is deliberately no large central foyer; instead, a continuous public route connects the spaces around the Grand Auditorium by means of stairs, platforms and escalators. The building becomes an architectural adventure.