Path: utzoo!utgpu!watserv1!watmath!att!occrsh!uokmax!munnari.oz.au!samsung!usc!chaph.usc.edu!alcor.usc.edu!alves From: alves@alcor.usc.edu (William Alves) Newsgroups: comp.music Subject: Re: Abs. pitch, intervals, and other musings (was Re: Perfect Pitch) Message-ID: <10626@chaph.usc.edu> Date: 6 Jul 90 00:23:21 GMT References: <1415@yenta.alb.nm.us> <3434@psivax.UUCP> Sender: news@chaph.usc.edu Organization: University of Southern California, Los Angeles, CA Lines: 51 In article ericm@FtCollins.NCR.com (Eric.Mintz) writes: > >Though I understand, in principal, the concept of tempered and >"pure" tuning, I have never (no my knowledge) heard pure tuning. Is >there any way I could tune my guitar to demonstrate the sound of pure >tuning? Unfortunately, your instrument is not a good one for demonstrating just intonation because the frets have been set into place (for each string) to facilitate equal temperament. However, you hear the difference between a just and non-just fourth every time you tune your instrument. When you tune the fourths between the strings so that there are no beats, you have tuned a just perfect fourth (4/3 ratio). This interval is about 2 cents flat of a fourth in equal temperament. Not a great difference, but enough to be noticeable. The difference between just and non-just thirds is much greater though, and can also be demonstrated on open strings. The way a guitar is normally tuned (E-A-D-G-B-E with perfect fourths up from the bottom E-A-D-G and down from the top E-B with the two E's in tune) will result in the ratio 81/64 between the G and the B, quite harsh in comparison with the just 5/4. In fact, the 81/64 third is a full 22 cents sharp of the just third (an interval called the syntonic comma), and the equal tempered major third is about 14 cents sharp. To hear the difference, try tuning the B string flat until the beats disappear. Of course you will no longer have a just fourth between the B and the E, but such is the dilemma of tuning. But unless you're playing all on open strings (or with natural harmonics, another way to hear just intervals), you won't be able to actually play in just intonation on an instrument with fixed frets. Variable tuning sys- tems are best suited to instruments with a separate sounding body for each pitch (such as a keyboard instrument or harp). Instruments with continuous pitch selection (fretless strings, voice, trombone) can also, of course, vary their tuning, but, in my experience, with less accuracy or consistency, especially with no external reference (such as playing along with a key- board instrument in that system). By the way, books, recordings, and software concerning alternate tuning systems are available from (with apologies to those who have seen this plug before): The Just Intonation Store 535 Stevenson St. San Francisco CA 94103 (415)864-8123 Run by the Just Intonation Network, this store has a catalog which they'll send to you. Membership in the Network will get you discounts and a sub- scription to their journal. Bill Alves