source file: m1452.txt Date: Fri, 19 Jun 1998 18:16 +0100 (BST) Subject: Re: Prima Sound From: gbreed@cix.compulink.co.uk (Graham Breed) Paul Erlich wrote: >The text is a little bit ambiguous >as to the exact tuning. Can anyone decipher it from the .wav or .mid >files at the site? My guess is that it is based on a chain of four 7/4s: >Ratio Cents >1/1 0 >2401/2048 275 >343/256 506 >49/32 738 >7/4 969 Theory is apparently explained at http://www.primasounds.com/prima.html, but I can't retireve the page. Maybe this is like the instructions to Mornington Crescent (to choose an analogy most people won't understand). >(although the page does suggest that "very little tempering" is used to >adjust these frequencies for some reason). With tuning to exact 7/4s, intervals between adjacent notes will be 8/7, except for one that is 44 cents sharper. Tempering would be to make it more like 5-equal. Analysing one of the .au files, this seems to be the case. I make the scale this: 1 8 64 7 2 - - -- x - - 1 7 49 4 1 (They should look like fractions if you're in monospaced mode.) The note x is tempered midway between the two adjacent notes. So, those intervals are 22 cents sharp of 8/7. I measured this accurately enough that it can't be 5-equal. It is particularly difficult to count the cycles of the tempered note, but I think I've got it right now. The answer I get is spot on to the nearest millioctave. It may be they've done something clever like play the two just notes together. Gary Morrison wrote: > Ever since I discovered 10TET's decent approximation to 7:4 (10TET >was my first microtonal tuning), I've found 7:4 a very nifty-sounding >interval. But I really don't see any call for mysticizing it. To quote from the site: >The frequency and harmonics of the acoustic seventh interval are >dissonant with all of the other basic fractions. For this reason it is >said to have no place in Music. With friends like that does it really need enemies? Graham Breed gbreed@cix.co.uk www.cix.co.uk/~gbreed