Respuesta :
Most vibrating things have several resonant frequencies, and musical instruments often vibrate at harmonics of the fundamental frequency. An integer (whole number) multiple of the fundamental frequency is defined as a harmonic.

In a Piano the relation between harmonic and resonance frequency is n_{1} : n_{2} : n_{3} = 1:2:3.
What is harmonic and resonance ?
"It is wave having frequency which is multiple integral of the fundamental frequency. The fundamental frequency is called first Harmonic. If a body starts vibration under impact of external vibrational force , is called Resonance. Since a Piano can produce all type of frequencies due to resonance therefore it produces melodious sound. Hence relation between harmonic and resonance frequency is n_{1} : n_{2} : n_{3}= 1:2:3."
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