Located on a jetty in the San Francisco Bay, the Wave Organ was built in 1986. In collaboration with the Exploratorium, artist Peter Richards built an acoustic sculpture that amplifies the sounds of the waves in the bay.

The organ’s jetty was constructed with carved granite and marble from a demolished cemetery. Magnificently old and finely worked pieces form the irregular terraced seating and even a trash can holder. The instrument itself is comprised of more than 20 PVC and concrete pipes that extend down into the water at various elevations. The sound is created by waves crashing against the ends of these pipes. When the waves roll in, the pipes resound with liquid music: low, gurgling notes that ebb and flow with the restless movement of the ocean and the changing of the tides.

What makes the music? It is similar to the phenomena of the sound heard in a conch shell—a specific volume of air resonating at a specific frequency. The same sort of thing happens in the pipes of the Wave Organ, but there is one important difference. In the Wave Organ, the columns of air within the pipes constantly change as the water moves in and out, and as the length and volume of the air column in each pipe changes, the pitch of the sound it produces also varies. The larger the volume of air, the lower the sound; the smaller the volume of air, the higher the sound.The park-like setting on the lee side of the breakwater has a view of San Francisco’s Marina District, downtown San Francisco’s skyline, the East Bay hills, Sausalito, Mt. Tamalpais, the Presidio, the Golden Gate Bridge, and the Marin Headlands. Fishermen are often at the organ in the morning, which after the walk by the marina can feel like a detached place of peace within the city.