3rd bridge
The 3rd bridge is an extended playing technique used on the electric guitar and other string instruments that allows a musician to produce distinctive timbres and overtones that are unavailable on a conventional string instrument with two bridges (a nut and a saddle). The timbre created with this technique is close to that of gamelan instruments like the bonang and similar Indonesian types of pitched gongs.
For other uses, see Third bridge (disambiguation).
Third bridge instruments can be custom-made by experimental luthiers (as with guitars designed and played by Hans Reichel); modified from a non-third bridge instrument (as with conventional guitars modified with a pencil or screwdriver under the strings[2]); or may take advantage of design quirks of factory-built instruments (as with the Fender Jazzmaster, which has strings that continue from the "standard" bridge to the vibrato mechanism).
Perhaps the best-known examples of this technique come from No Wave artists like Glenn Branca and Sonic Youth. The 3rd bridge technique has a physical connection with Pythagoras' monochord, because both function with the scale of harmonics. Many non-Western musical scales and musical instruments share these consonant just pitch relations.
Without the 3rd bridge[edit]
The sound effect can be achieved without an additional 3rd bridge or extended tail piece. If the player presses on a fret (not behind it, as with standard fretting) and strums the string at the head side, the resonance comes through. Again, on harmonic positions the result is much louder and clearer than on the inharmonic fret positions. The 5th, 7th, 12th and 19th fret generate low-frequency humming overtones with the complementary tone, which is usually played in the regular way. This playing technique causes a smooth, round multiphonic sound. By muting the resonating part and letting it go after the pluck it sounds like an inverse recorded sound. On all other positions the tone is more undefined and comes with higher pitched lower volume overtones. With heavy distortion these tones can become more clear.
Bowing behind the bridge[edit]
The technique is widely used in many modern classical works on bowing instruments. The extended technique involves bowing the instrument on the afterlength, the short length of string behind the bridge. The tone is very high and squeaky. By playing the instrument at a string part behind the bridge, the opposed part starts to resonate. The tone is louder at harmonic relations of the bridge string length. On violins, the tone can be very high, even above the range of human hearing. Depending on the instrument, the pitch of the tones may or may not be perceived (cellos and double basses are more likely to produce recognizable pitches because of their longer strings). This technique is used extensively in Krzysztof Penderecki's Threnody to the Victims of Hiroshima. Another example is found in Ferde Grofé’s Grand Canyon Suite where bowing behind the bridge in a violin cadenza represents a donkey’s braying.