The harp is one of the oldest stringed instruments, with origins in ancient Egypt and Sumer. A modern 'pedal harp' (or concert harp) is a highly complex machine. It features 47 strings and seven foot pedals. These pedals allow the harpist to change the pitch of the strings while playing, enabling the instrument to play in any key—something ancient harps could not do. Each pedal has three positions (flat, natural, and sharp). The strings are traditionally color-coded to help the musician: all C strings are red, and all F strings are black or blue. Harps are unique because the strings run vertically from the soundboard to the neck. The instrument is famous for the 'glissando'—a sweeping sound created by running the fingers across the strings—which is a staple of orchestral music used to create dreamlike or magical atmospheres.