Guitar manufacturing is the use of machines, tools, and labor in the production of electric and acoustic guitars. This phrase may be in reference to handcrafting guitars using traditional methods or assembly line production in large quantities using modern methods. Guitar manufacturing can also be broken into several categories such as body manufacturing and neck manufacturing, among others. Guitar manufacturing includes the production of alto, classical, tenor, and bass tuned guitars (with classical being the most widely used tuning). A single person professionally trained in guitar manufacturing is called a Luthier, although luthiers typically create other stringed musical instruments as well. For a list of large scale guitar manufacturing companies, see this list of guitar manufacturers.