The demonstration monochord investigates the relationship between the pitch of a sound and the length of the string. Also investigate overtones formed by harmonic waves with intermediate nodes and the dependence of the pitch on string tension. Two steel strings and one nylon string are stretched over a sound box. Alter the tension on the two strings using tuning pegs while simultaneously changing the third string with weights or a dynamometer. Change the effective length of the strings by moving the two bridges. Scale length: 600 mm.