Only recently, have we learned how to tune guitars. I don't mean tuning the strings up to pitch, but tuning intervals on the fingerboard. Everyone knows how frustrating it is to try to tune different chord shapes, especially at the lower end of the neck. You can see it on even the most basic electronic tuner.
As a kid, I took my guitars to the best shops in Nashville and basically, I got screwed!! I'd spend $80 on repairs and nothing.That was a lot of money in 1967 and I still had major tuning problems!! Now, to be fair, they didn't have laser calibrated strobophonic tuners with digital readouts!! They were just a bunch of good ol' boys that spent their time upstairs after hours setting the sights on their rifles and shotguns. As I grew as a player, so did my demand for better instruments.
Most musical instruments don't have the tuning demands placed on them that guitars have. Maybe the piano,.. but only in the sense that it is required to play in all keys,.. like the guitar. Other instruments like brass or woodwinds are speciffic to their own resonance in an orchestral sense. If guitars only had to play in the key of "D", or "A",.......no problem!! We could position the frets accordingly with little need to adjust intonation!!!
I now offer my NepTune interval correction as a modification for existing guitars. I have been very successful at modifying commercial guitars with this modification. This is done through a series of mathematical formulas pertaining to the style and kind of guitar, and then factor in the scale length. It is well worth the costs for the upgrade.($175 for electric guitars, $325 for acoustics) Every guitar is different and has it's own set of problems that need to be addressed. I've performed over 200 modifications at this time. On all of the guitars that I build, the NepTune system is already integrated!