Geophone (musical instrument) Geophone (musical instrument) 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
Triangle (musical instrument) Triangle (musical instrument) The triangle is an idiophone type of musical instrument in the percussion family. It is a bar of metal, usually steel but sometimes other metals such as beryllium copper, bent into a triangle shape. The instrument is usually held by a loop of some form of thread or wire at the top curve. "It is theoretically an instrument of indefinite pitch, for its fundamental pitch is obscured by its nonharmonic overtones." Triangle has a prestigious history. The triangle in its ancient form had rings strung to the lower bar. Yet the first mention we find of a