shells, such as the previously mentioned Queen Conch (Strombus gigas),
the Giant Triton (Charonia tritonis) and the Horned Helmet (Casis
cornuta) come in various shapes and sizes. The bigger the shell,
the lower the tone. On any given shell only a limited number of
notes can be played. This means that a greater number of musicians
are needed to play a melody.
Shells have been and still are used throughout the
world for signalling and communication. At sea as a foghorn (eg.
The Netherlands, France), at war as a call to battle (Japan), in
religious ceremonies (India, Nepal), to ward off evil spirits (New
Guinea) and at the birth or death of important tribal members (Oceania).