Sackbut Sackbut A sackbut is a type of trombone from the Renaissance and Baroque eras, characterised by a telescopic slide that is used to vary the length of the tube to change pitch. Unlike the earlier slide trumpet from which it evolved, the sackbut possesses a U-shaped slide, with two parallel sliding tubes, which allows for playing scales in a lower range. Records of the term "trombone" predates the term "sackbut" by two decades, and evidence for the German term "Posaune" is even older. "Sackbut", originally a French term, was used in England until the instrument fell into disuse in the
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