THE best seminar I have ever attended on JI vs ET training used a big Martin D-45 (I believe it was). The instructor's first thing was to strum that big open E chord. And it was incredibly beautiful to all who heard it.
Then the instructor said, listen to this. He then strummed an open C chord. And oh my, how awful it was. The instructor mimicked what many have said (or heard) over the years with the following statement,
"Sumthuns wrong wid this git' tar!!. They musta putt tha frets on wrong!", Along with a few more "good ole boy" euphamisms.
Then the instructor (wisely) spent the next hour and a half, showing AND proving WHY, the E Chord and the C chord can NEVER be tuned JI symultaneously. He did this by retuning the guitar to make the C chord sound beautiful and of course the E chord sounded horrible. Along with several more very lucid and appropo demonstrations.
Then the instructor went on to show us how to get the best compromise. He said,
"Widen your fifths
* and narrow your fourths
* just a little". And as he did this, his E chord AND his C chord sounded pleasing symultaneously, albeit neither chord was as pretty (to most of our ears) as it was by doing this widening and narrowing thingy.
This of course just typifies the age old battle of the regular guitarist. It even affected the late and great Chet Atkins, because he was heard many time to blare out the following frustration,
IF I ever get this git' tar in tune, I'm gonna solder it!!"
Course, in 17e zillion years, he, nor anyone else is EVER going to get a guitar "in tune". It is not going to happen. At least it is not going to happen as long as man uses the most inneficient testing device ever created.
The human ear!
* The instructor used widening and narrowing incorrectly in his anaology. Technically he was correct, musically he was incorrect. He should have said "Widen the 4ths, and narrow the 5ths a little bit."
Bless his heart, his error was a result in using the E note in reference to B rather than using the B note in reference to an E. The reason for this is. We were talking about an E chord, NOT a B chord.
The other interesting thing was, what the instructor possibly did not know (although he may have), was narrowing the 5ths (which is the SAME as widening the 4ths) just so happens to be ET!!.
enuff said.
carl