I am seeing a common theme in Calatrava’s work.  He really likes to create different structural forms to represent his projects. The Milwaukee Art Museum has a whimsical aesthetic that he modeled to look like the wings of a bird. His abundant use of steel and glass created a space that highlights its art inhabitants while at the same time tipping its hat to great architecture. The shape of the concrete reminds me of similar modern architecture used in designing airports in the late 50s and early 60s.