The geophone is a percussion instrument, invented by the French composer Olivier Messiaen for use in his large composition for piano and orchestra entitled Des canyons aux étoiles... ("From the canyons to the stars..."). It consists of a drum filled with thousands of small lead pellets, and is played by swirling it around slowly so that the noise of the pellets resembles the sound of dry shifting earth.
Messiaen commissioned a Parisian instrument maker to construct one to his design, and he carried this instrument worldwide to early performances of the piece (which was given its first performance in New York City). Messiaen's wife, Yvonne Loriod, commented that when she and the composer first collected the new instrument from the maker in her car it made a "splendid crescendo" whenever they went round a corner.
Messiaen also included the instrument in his only opera, Saint François d'Assise, which was first performed in Paris 1983. Other works that use the geophone include Asyla by Thomas Adès, ...towards a Pure Land by Jonathan Harvey, and the operas The Sacrifice by James MacMillan and Dark Sisters by Nico Muhly.
This article relies largely or entirely on a single source. (November 2010)