Making an instrument of the violin family may be done in different ways, many of which have changed very little in nearly 500 years since the first violins were made. Some violins, called "bench-made" instruments, are made by a single individual, either a master maker, or an amateur working alone. Several people may participate in the making of a "shop-made" instrument, working under the supervision of a master. Various levels of "trade violin" exist, often mass-produced by workers who each focus on a small part of the overall job, with or without the aid of machinery.