 Likewise strings with less mass per unit length, if under the same tension, will have a higher frequency and thus higher pitch than more massive strings.This is a prime reason why the different strings on all string instruments have different fundamental pitches, with the lightest strings having the highest pitches.A played note of E or F has a frequency which is often very close to the natural resonating frequency of the body of the instrument, and if the problem is not addressed this can set the body into near resonance.