An upright piano is a musical instrument with a keyboard, pedals, and vertical metal strings inside of a rectangular framework. Its length and width are approximately equal to those of a standard desk, while its height is comparable to the combined height of two standard desks. It is mostly made of wood and metal; the wood that covers the exterior of the instrument has a polished appearance. The function of an upright piano is to produce sounds that are similar to the sounds from one’s voice box, as they vary in pitch, volume, and duration.