Vibrating string, amplitude harmonics. Animation showing a number of oscillating strings fixed at both ends, demonstrating amplitudes and harmonics. This animation shows the vibration of six strings: three in the first harmonic, three in the third harmonic. Each set of strings vibrates with a different amplitude. This animation shows that the frequency depends on the harmonic, but not on the amplitude (this is valid for 'small' amplitudes). This model is a numerical simulation that models each string as several thousand elements. Each element is driven by a restoring force proportional to its deflection from the rest position, and an inertial force due to its mass.