The violin was first made in Asia about 450 years ago. The violin is made of wood and the strings are made of metal. The E string is a single strand of wire but the G-string has a single strand of wire with another string wrapped around it. To make the pitch higher you tighten the string and to lower the pitch you loosen  the string. To do this you use the fine tuners or the pegs. There are 4 strings, G, D, A, and E. E is the highest note and G is the lowest note. The strings vibrate to make the sound.