The rich decoration of the façade of the Palau, which incorporates elements from many sources, including traditional Spanish and Arabic architecture, is successfully married with the building's structure. The exposed red brick and iron, the mosaics, the stained glass, and the glazed tiles were chosen and situated to give a feeling of openness and transparency. Even Miguel Blay's massive sculptural group symbolizing Catalan music on the corner of the building does not impede the view into or out from the interior
Two colonnades enjoy a commanding position on the second-level balcony of the main façade. Each column is covered uniquely with multicolored glazed tile pieces in mostly floral designs and is capped with a candelabrum that at night blazes with light. Above the columns are large busts of Giovanni Pierluigi da Palestrina, Johann Sebastian Bach, and Ludwig van Beethoven on the main façade and Richard Wagner on the side. The top of the main façade is graced by a large allegoric mosaic by Lluís Bru that represents the members of the Orfeó Català, but it is impossible to see it clearly from the narrow street below.