What’s 3^rd Bridge?

This text explains the term ‘3^rd Bridge’ and what’s the use of adapting your guitar in such a way or even, what Bradford Reed and I did, built an instrument especially focused on this technique. This is only a short description as a clarification for people not familiar with the phenomenon at all. A longer text is my article 3rd Bridge Helix on furious.com diving more in depth into this subject.

Playing 3^rd bridge is adding an extra bridge on a string instrument. This can be anything simple like a screwdriver or a pencil put between the fretboard and the strings. When you pluck the string at the neck side, the opposed part starts to resonate along and a strange multiphonic tone appears, consisting of a bright overtone and a humming tone (and a very low volume third tone, but I skip that one, since that’s not very relevant for this explanation). The position of the extra bridge is very relevant for the tone combination. It can sound like a Harp, a Piano string, a Clock, a Japanese Koto, a Bell, a Sitar or an even more dry percussive sound like for instance the sound of a Wood block or a Piece of Metal. The sound of it is clearly audiable on the Sonic Youth album Confusion is Sex.

The summarisation of instruments is not choosen random. The sound of the multi-tone is connected to the harmonic positions of the string. These are mathmatic equal parts out of the serie 1 + 1/2 + 1/3 + 1/4 + 1/5 + etc., as well as their multiples 2/3, 3/4, 2/5, 3/5, 4/5, etc.

When the extra rod is placed on one of the more simple fractions the volume of the overtone increases and becomes very bright. On more complex fractions the tone becomes lesser loud and short in sustain even up to immediatelly dead at very high string fractions.

An oversight of the sounds appearing at the mathmatical positions:

1/2 Harp

1/3, 2/3 Bluthner Piano

1/4, 3/4 Clock

1/5 – 4/5 Clock

1/6 Koto

1/7 – 6/7 Bell

1/8, 3/8, etc. Bell

Higher fractions Bell or dry percussive sounds

Unsolid bridge can cause a buzzing sound remniscent of the sound of a Sitar

One major problem with adapting a guitar is you only have 6 clean tones available, since the fretboard is no longer working properly. Another annoying aspect is the difficulty of reproducing a sound later on again. The position is a very precise parameter of the result. 2 mm defiation can lead to very big sound differences. The third problem is the screwdriver or pencils slipping out of position while playing your song on stage leading to an annoying unwanted chaos.

Those were the three reasons for me to start on trying to make my own 12-string instrument solving those issues. After finishing the instrument for Aaron Hemphill of Liars, I discovered how much ‘truth’ the preparation technique contained, as written out in the 3^rd Bridge, Helix of Consonance article on furious.com.

3^rd Bridge on my other instruments

The 3^rd Bridge technique is most worked out on the Moodswinger, but also on some of my other instruments the theory is taken along within the construction somehow. The Springtime and Twister both have a tailed bridge for this reason. The Springtime has a 5:1 ratio and the Twister a 4:1 ratio, both leading to an unique sound possibillity of their own kind.

See also

Guide how to Prepare a Guitar – by Yuri Landman

Luthéal – Experimental 1914 piano

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