A pun on Just Intonation,
coined by Robin Perry to describe the fretboard of
a guitar he had specially made. (In colloquial English,
"just about" means "quite close to, but not exactly".)
The guitar had
frets which went straight across the fretboard as
on a regular guitar, but which were spaced so that
they emulated many JI ratios
within +/- 5 cents resolution
(i.e., 240edo).
Here is a description from
Yahoo
tuning list, message 14767:
From: Robin Perry
Date: Fri Oct 20, 2000 8:19am
Subject: Re: my just-about guitar
Dear Tuners...
Monz wrote:
>> > > The only guitars I've seen that come close to real JI while still
> > > using straight frets across all six strings, are the guitars
> > > refretted by Robin Perry which he calls 'just-about intonation'.
> >
> > > One guitar Robin lent me has 3 different fret distances: 70, 85,
> > > and 115 cents. On any given string, this produces scale-steps
> > > that give close approximations to such ratios as 10/9, 7/6, etc.
> >
> > How does Robin tune his open strings?
> To be honest, I'll have to write him and ask... too bad he's not
> on the List anymore. As a general rule, he tunes the open strings
> to a JI (or pseudo-JI) chord, but of course any tuning at all can
> be used for the open strings, including one that more closely
> resembles the 'regular' tuning.
>
> I wrote a very brief description of this guitar 7 months ago,
> right after visiting Robin during my road trip west:
>
>
> > me, monz:
> > http://www.egroups.com/message/tuning/8889
> >
> > It has 3 different sizes of frets which go straight across
> > the neck: 70 cents, 85 cents, and 115 cents, in this repeating
> > pattern:
> >
> > || | | | | | | |
> > || 70 | 115 | 85 | 115 | 115 | 85 | 115 |
> > || | | | | | | |
> >
> > Most of you should be able to see right away some
> > of the just ratios that it approximates well. The tuning of the
> > open strings is completely 'user-definable', but Robin generally
> > uses tunings which produce a nice rich JI chord on the open strings.
>
>
> To the best of my recollection, he tuned this particular 'Jinto'
> guitar to a pseudo-JI 'major 9th' chord.......
Yes, I still am on the list, and still, unfortunately, so swamped with
L.O.T.T. (life other than tuning) my "reading" on the list is mostly
scrolling. My posts, such as they are, are on the skimpy side.
The tunings I used for the Just-about were, as Joe said, basically open
chords. From any fret on this guitar, you can move up in either a 1/2/5
a 1/4/5 type progression and in some cases, both. There are many other
chords accessible of course, but you really have to study the relationships
to get something worthwhile out of it. The resolution of the just-about is
to the nearest five cents (240 TET).
I decided to have the guitar re-fretted the way I did because I felt that
the fret spacing in the higher number E.T.s would be beyond me. I wanted
something close to 12 TET spacing. I have since re-thought that limitation
and want to get hold of a 31. If mandolin players can get used to it, why
can't I?
Robin Perry
Charlottesville, VA
[from Joe Monzo, JustMusic: A New Harmony]
