 Other links through shared resonances occur at the fifth and, though with much less effect, at the major third.The principle of sympathetic resonance has been applied in musical instruments from many cultures and times.Apart from the basic principle at work on instruments with many undamped strings, such as harps, guitars and pianos with the dampers raised, other instruments are fitted with extra choirs of sympathetic strings, which respond with a silvery halo to the tones played on the main strings.