<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: Rocking bridges</title></head><body> <div>The phenomenon of the piano bridge rocking and of this bodily rocking motion of the bridge contributing to the transfer of the note produced by the string to the soundboard has been put forward repeatedly by Ron N., Ron O. and Del.</div> <div><br></div> <div>I would like to consider this interesting and undocumented theory at a very basic level.</div> <div><br></div> <div><img src="cid:a0510030ab84ad1de24ec@[195.147.233.234].1.0"></div> <div><br></div> <div>To simplify things I thought it would be a good idea to eliminate as far as possible any impediment to the bridge's rocking, such as the tension of the other strings and the fixing to the soundboard, so the drawing above shows a string (s) of some material stretched between two pins (p) and passing over a bridge (b) that is curved at the bottom to allow it to rock and roll. The string (s) cannot slide over the bridge top.  Out of the top of the bridge comes a needle (n) that ends in a pointer (a) running round a scale (d).  Clearly if pressure is applied to the string at s or anywhere, the pointer (a) will move clockwise as the bridge (b) rocks and will return to zero when the pressure is released.  The base can be considered anything fairly rigid and is not pertinent to the design; it is in no way to be considered a representation of a soundboard.</div> <div><br></div> <div>I will describe the device in more detail once it is accepted as a realistic schematic representation of a stringed instrument with a bridge that is more than usually free to rock.</div> <div><br></div> <div>JD</div> <div><br></div> </body> </html>