A study of the Pedestrian Bridge Katehaki, designed by Santiago Calatrava in Athens, presented as an imaginary Concert for Harp, played at just one instrument, the photographed object itself. Many of the Calatrava bridges remind of instruments with strings and generally his organic style in architecture sends the mind of the viewer towards music. The elegance, the fact that most of his bridges are cable-stayed, the asymmetrical shape of the suspending element remind all of rhythm, detail, sound, music. Based on the fact that a shape can be associated in the mind of the viewer with sounds and taking in consideration the shape of the bridge I photographed, I imagined the orchestra as being made of different kinds of harps, by emphasizing in each image a different angle and detail of the bridge, but always accentuating the part that creates the sound: the strings. That's why the viewer will find the bright streak of light on the cables, it is the sound that the wind makes when passing through the strings, creating music.