The Palau Musica de Catalana is a concert hall designed by architect Lluis Domenech Montaner (not Gaudi!) that opened in 1908. This building is the headquarters of "Orfeó Catala", a prestigious institution founded in 1891 to support Catalan music and culture.
The concert hall of the Palau is an awesome spectacle. It is illuminated virtually entirely in natural light, via ornate stained-glass panes. The centerpiece is an enormous inverted dome skylight designed by Antoni Rigalt, in shades of gold surrounded by blue, that suggests the sun and the sky. The acoustics in the room were quite good but it was the soft magical lighting in the hall that impresses the most.
I was disappointed that photography inside the concert hall is not permitted. That the owners choose to limit photography of such a magnificent building, which is virtually a shrine to light and creative artistic achievement, is a shame in my opinion. A more reasonable policy has been adopted in the Gaudi exhibits, which allows photography but restricts usage of images for commercial purposes. I took the image above 'from the hip' so it is not well composed, and will take it down if asked, but I maintain that such a policy is just plain silly - I have no intention of selling this image.
The facade of the exterior of the building is interesting but very difficult to photography given the narrow streets that surround the building. The exterior is mostly memorable for the floral designs. The appearance was a bit too much like a wedding cake for my taste, but still quite interesting.