source file: mills2.txt Date: Thu, 9 Nov 1995 15:44:02 -0800 Subject: guitars, slides & harmonics - simple help wanted From: chad@cix.compulink.co.uk (Charles Dignes) In-Reply-To: <199511091619.IAA05972@eartha.mills.edu> Dear All, I have just returned from gigging in Istanbul, home of the multi-fretted long-necked lute (saz et al.), still coughing the cigarette-smog of 15million chain-smoking Turks out of my poor old lungs, but happy and bearing fine spoils. I can report that micro-tonalism is alive and well; I told my Gypsy friends about you all and they said to send greetings. But Lachio! This + the many recent wild and whacky postings has inspired me to take down my good old occidental 5-string open-tuned acoustic guitar and play about with an old slide thing I found some years back. Seeing as how there be less mathematically-challenged folk out there than myself, I was hoping one such kind person might be able to help me with a couple of problems that have been nagging at me for the last decade or so. 1. Firstly, does anyone have an idea of the mathematical expression (algorithm?) for the following: * Get acoustic guitar and slide. * Place slide at the octave, i.e. half-way point of the string, strike both sides. Result = same note. * If you then move the slide up (or down) and continue to strike both sides of the string, certain "nodes" emerge in which with each side of the string harmonises, according to the relationship - i.e. "perfect" third, fourth, fifth etc... For example: if the string in question is a G, then going up the neck towards the nut you will pass from: unison (g) | (g) - at the half-way length of the string, to: octave (d') | (d) - at the third-way length of the string. Although many of these nodes are the expected ones, plenty are "out" of the standard "g" harmonic series. For example, the minor 3rd is near enough a quarter-tone and the 7th is decidedly skew. Questions: Maybe people have been going on abut this under some other name, if so what is this sort of harmonic collection called? What is the mathematics of this as a whole series? Are there any proper big compositions & works in this field of, I suppose I'd call it "bifurcative-JI"? Is it possible to play this in yet another plane (i.e have not 2 but 3 floating sliding points in the frequencu spectrum)? Is this a bit like what Brian McLaren is talking about with rhythm? 2. My second request is of a similar nature, but more practical and applies to anyone who is interested in the visualisation of fretless finger-stopping (as opposed to diagrams of music!), who has a computer and means op generating waving nice wavy patterns (sine, cosine will do). I have this thing called a cümbüs (that's pronounced jumbush with puckered lips for the u umlauts). It's about the hardest animal I ever encountered but essentially it is a 12-string fretless banjo. The neck is bolt-on and the fingerboard is made of (if you please) a formica strip. Cheap & cheerful and the best friend the hard-working 7-days-a-week, 5-hours-a-night Istanbul Gypsy twangers have. Louder than an Ud, less of a loss if drunken revellers are sick on it, have to be controlled etc. Also good for cooking up some rice in. If I can provide the exact dimensions of the fingerboard, tuning of strings, string scale length etc... can anyone knock me up a nice wavy pattern that approximates the "tree of life" design found on all the nice old bouzoukis? This is a traditional sinuous curvy thing with vine leaf bits coming off it. I have PC running MS things and access to Quark and other bigger apps. Essentially I am looking for a visual aid to a fretless fingerboard that I can cut into the fingerboard so I can encourage myself to play other forms of tuning. I imagine something a bit more modern than vine-leaves, lots of super-imposed sine and cosine waves that produce nice, moire patterns, super-imposed over standard, or JI or 14ET fretting marks etc... Hoping this is of interest or at least germane to the current (wonderful high level) of postings & discussion, and apologies if not. All responses gratefully received. Lu aka: chad@cix.compulink.co.uk London, UK Received: from eartha.mills.edu [144.91.3.20] by vbv40.ezh.nl with SMTP-OpenVMS via TCP/IP; Fri, 10 Nov 1995 04:23 +0100 Received: from by eartha.mills.edu via SMTP (940816.SGI.8.6.9/930416.SGI) for id SAA25068; Thu, 9 Nov 1995 18:23:44 -0800 Date: Thu, 9 Nov 1995 18:23:44 -0800 Message-Id: Errors-To: madole@ella.mills.edu Reply-To: tuning@eartha.mills.edu Originator: tuning@eartha.mills.edu Sender: tuning@eartha.mills.edu