Standing waves (17.5)
Length of vibrating material is fixed (e.g. string, column of air in wind instrument, violin string, …)
Standing wave patters, each pattern corresponds to a unique frequency
Smallest frequency f1: first harmonic or fundamental
Higher frequencies are integer multiples of f1 (2f1, 3f1, 4f1, …) and called 2nd, 3rd, 4th, … harmonic or 2nd, 3rd, 4th overtone.