Two art installations in Zadar, Croatia are featured in the video above. The "Sea Organ" uses the power of ocean waves to generate sounds from organ pipes embedded in a shoreline structure, as explained at OddMusic:
Each musical organ pipe is blown by a column of air, pushed in turn by a column of wave-moved water, through a plastic tube immersed into the water. The pipes' musically tuned sounds emanate to the surroundings through apertures in the vertical planes of the uppermost stairs. The 7 successive groups of musical tubes are alternately tuned to two musically cognate chords of the diatonic major scale. The outcome of played tones and/or chords is a function of random time and space distribution of the wave energy to particular organ pipes.The nearby solar-powered light installation is explained at Physics Buzz (whence the video).In this part of Croatia the prevailing musical tradition is the spontaneous four-voice male singing, with melodies and chords conforming to the diatonic major scale. The 5 musically tuned pipes of each section are arranged in 1.5 meter spacings. A listener, standing or sitting on a chosen point on the scalinade, should be able to hear 5 to 7 musically tuned pipes play their natural music. Thus, whole five-pipe sections are tuned to one musical chord. The citizens of Zadar are extremely proud of the first natural musical organ driven by the sea waves ever to be constructed...
