There is a type of instrument called a Tidal Organ which uses the tides as its player. One such organ is located in Zadar, Croatia. The organ was made by architect Nikola BašIć as part of a project to redesign the new city coast and was opened to the public in April of 2005.
Much of the seafront in Zadar was destroyed during WWII and in an attempt to quickly fix it, much of the seafront was turned into a plain concrete wall. The organ was a response to this and has succeeded in bringing tourists and locals alike to the site.
Marble steps that lead down to the water are what you can see on the outside, but underneath those stairs is a system of tubes and a resonating cavity which turns the whole thing into an instrument which plays somewhat random, yet harmonic, sounds. The sounds emerge from holes along the top step.
In addition to the Sea organ, there are a few other tidal organs around the world. The Wave organ is located in San Francisco, which carries the natural sounds of the waves and their interaction with the pipes to listeners at several different stations. The High Tide Organ is another tidal organ which is located in the town of Blackpool, England. This organ features a 50 foot tall sculpture described as a "musical manifestation of the sea.”
