Sympathetic string

Sympathetic strings or resonance strings are auxiliary strings found on many <a href="/facts/Music_of_India/yFwovhbY">Indian</a> musical instruments, as well as some Western <a href="/facts/Baroque_music/UgrJnyTq">Baroque</a> instruments and a variety of folk instruments. 
They are typically not played directly by the performer (except occasionally as an effect), only indirectly through the <a href="/facts/Tone_(musical_instrument)/2xIp3q8v">tones</a> that are played on the main strings, based on the principle of <a href="/facts/Sympathetic_resonance/CMWTQKNL">sympathetic resonance</a>. 
The resonance is most often heard when the <a href="/facts/Fundamental_frequency/TJBJKHow">fundamental frequency</a> of the string is in unison or an <a href="/facts/Octave/RA4gWvkV">octave</a> lower or higher than the catalyst note, although it can occur for other <a href="/facts/Interval_(music)/aFwkkgpY">intervals</a>, such as a <a href="/facts/Perfect_fifth/PTIaHPuI">fifth</a>, with less effect.

Sympathetic string open-in-new

Sympathetic string