Editing Sympathetic string

[[File:Midtdetalj.jpg|thumb|[[Hardanger fiddle]], showing sympathetic strings underneath playing strings]]
[[File:Sarangi close-up crop.jpg|thumb|Detail of a sarangi, showing its sympathetic strings under three playing strings]]

'''Sympathetic strings''' or '''resonance strings''' are auxiliary strings found on many [[Music of India|Indian]] musical instruments, as well as some Western [[Baroque music|Baroque]] 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 [[Tone (musical instrument)|tones]] that are played on the main strings, based on the principle of [[sympathetic resonance]]. 

The resonance is most often heard when the [[fundamental frequency]] of the string is in unison or an [[octave]] lower or higher than the catalyst note, although it can occur for other [[interval (music)|intervals]], such as a [[perfect fifth|fifth]], with less effect.

==Description==
Sympathetic strings are used to enhance the sound of an instrument. Some instruments have only a few sympathetic strings such as the [[Hardanger fiddle]]  (pictured above right). Other instruments which have more include the [[sitar]] with 11-13 sympathetic strings and [[sarod]] with 15 sympathetic strings, and the [[sarangi]], which has a total of 37 sympathetics. 

In [[Classical music|Western music]], some members of the [[viola]] family appeared in the middle of the 17th century that were fitted with an extra choir of thin wire strings running through a hollow chamber through the [[Neck (music)|neck]] of the instrument, the head of which was then elongated to accommodate as many extra tuning pegs as necessary. These were generally called [[viola d'amore]]; another historical example is the [[baryton]], for which [[Joseph Haydn|Haydn]] wrote many [[Ternary form|trios]]. 

Other instruments such as the [[harp]], [[lute]], [[guitar]], [[harpsichord]], and [[piano]] do not have additional strings, but make use of the effect by allowing their playing strings to vibrate sympathetically when they are not being played directly. In [[keyboard instrument]]s like the piano, the string dampers can be raised to produce this effect.

The [[guitar]] is normally unable to produce effective sympathetic string resonance for tones other than E (resonance from the 6th and 5th strings, tuned to E and A, respectively), B (from the 6th string), D (from the 4th string), and A (from the 5th and 4th strings). The treble strings are negligible in practice, as they are almost constantly being fingered. 

However, the [[Ten-string guitar#Yepes' ten-string guitar|ten-string guitar]] invented in 1963 by [[Narciso Yepes]], adds four strings tuned to C, A{{music|sharp}}, G{{music|sharp}}, F{{music|sharp}}, which resolves the imbalance of resonance on the guitar. By adding the abovementioned resonances and, of course, their fifths (the fifth being a strong [[resonant frequency]])&mdash;that is to say, G, F, D{{music|sharp}}, C{{music|sharp}}&mdash;the guitar's strings now resonate more equally with all 12 notes of the [[chromatic]] scale, bringing the guitar's sound closer to the consistency and sustainability of the [[harpsichord]] and [[piano]].<ref>Ramirez III, Jose. 1994. "The Ten-String Guitar" in Things About the Guitar. Bold Strummer. pp. 137-141. {{ISBN|8487969402}}</ref><ref>Yepes, Narciso. 1981 "Narciso Yepes and His 10-String Guitar". Interview-Article by Allan Kozinn. The New York Times, Nov. 22: p. D21
</ref><ref>Yepes, Narciso. 1978. "The 10-String Guitar: Overcoming the Limitations of Six Strings". Interview by Larry Snitzler. ''Guitar Player'' 12(3): pp. 26, 42, 46, 48, 52.</ref>

==Sympathetic string resonance in music instruments==
{{main|String resonance (music)}}
Strings or parts of strings may resonate at their [[Fundamental frequency|fundamental]] or [[harmonic]] frequencies when other strings are sounded. In general, non-played strings respond in sympathy to other strings being played. Two tones of the same [[Pitch (music)|pitch]] will give maximum sympathetic resonance as all harmonics of both strings will overlap. Other harmonic combinations will cause sympathetic resonance at the fifth, fourth and major third. 

For example, an A string at 440&nbsp;Hz will cause an E string at 330&nbsp;Hz to resonate, because they share an [[overtone]] of 1320&nbsp;Hz (3 x 440 = 4 x 330 = 1320; third overtone of A and fourth overtone of E).

===Tuning===
The musician retunes the sympathetic strings for each [[Musical mode|mode]] or [[raga]], so that when the corresponding note (or one an octave below it) is played on the main strings of the instrument, the sympathetic strings (called ''tarabs'' in [[Music of India|Indian music]]) will vibrate in response, providing a lingering halo of sound.

==Instruments with sympathetic strings==
{{colbegin|colwidth=30em}}
*[[Banjo]]
*[[Baryton]]
*[[Bazantar]]
*[[Crwth]]
*[[Dilruba]]
*[[Esraj]]
*[[Fender Jaguar]]
*[[Fender Jazzmaster]]
*[[Gadulka]]
*[[Gottuvadhyam]]
*[[Gudok]]
*[[H'arpeggione]]
*[[Hardanger fiddle]]
*[[Dutar|Herati dutar]]
*[[Hurdy-gurdy]]
*[[Kithara]] (of [[Harry Partch]])
*[[Koto (musical instrument)|Koto]]
*Some instruments of the [[lute]] family
*[[Mohan veena]]
*[[Moodswinger]]
*[[Moonlander (musical instrument)|Moonlander]]
*[[Nyckelharpa]]
*[[Ondes Martenot]] (with Palme diffuseur)
*[[Pencilina]]
*Pianos that use [[aliquot stringing]]
*[[Prepared guitar]]
*[[Prepared piano]]
*[[Rubab (instrument)|Rubab]]
*[[Samvadini]] (stringed harmonium)
*[[Sarangi]]
*[[Saraswati Veena]]
*[[Sarod]]
*[[Setar]]
*[[Sitar]]
*[[Springtime (guitar)|Springtime]]
*[[Tanpura|Tambura]]
*[[Tar (lute)]]
*[[Taus (instrument)|Taus]]
*[[Ten-string guitar]]
*[[Ukelin]]
*[[Viola d'amore]]
{{colend}}

==See also==
*[[Aliquot stringing]]
*[[Drone (music)]]

==References==
{{Reflist}}

{{Timbre}}
{{Authority control}}

[[Category:Chordophones]]
[[Category:Timbre]]