Violin construction and mechanics four open strings, usually tuned to G, D, A, and E. The strings run from a tailpiece attached to the base, across a wooden bridge, continue towards the neck of the instrument running parallel to the fingerboard, and connect to the pegbox located at the very top of the violin. They are wound around four tuning pegs that are mounted sideways through holes in the pegbox. The bridge helps to hold the strings in place, while the pegs maintain the tension necessary to produce vibration. Strings were first made of sheep's intestines (called "catgut"), stretched, dried and twisted. Contrary to
Musical instrument classification percussion instruments made of wood or metal ("Ghana vadya", "solid instruments"); and percussion instruments with skin heads, or drums ("avanaddha vadya", "covered instruments"). Victor-Charles Mahillon later adopted a system very similar to this. He was the curator of the musical instrument collection of the conservatoire in Brussels, and for the 1888 catalogue of the collection divided instruments into four groups: strings, winds, drums, and other percussion. This scheme was later taken up by Erich von Hornbostel and Curt Sachs who published an extensive new scheme for classication in "Zeitschrift für Ethnologie" in 1914. Their scheme is widely used today, and