What I am wondering is, do our ears really have the sensitivity to tell the difference between the tone of an Indian Rosewood back over a Brazilian Rosewood back?
To simplify, is a rosewood species equivalent, in general, when it comes to tone? Likewise, is mahogany species a mahogany tone. Now I understand that density can play and overall role in tone but are the variations in the same genus or even the same species significant enough to say that one is superior over the other? Are we paying for "appearances" when it comes to rosewoods (for example) or is there really an argument for unique tone?
Also, is a soundboard like Adirondack really superior to sitka? Can our ears really notice it? Is bearclaw sitka really superior to standard sitka? I played a dreadnaught with an adirondack top and indian rosewood back at it was indeed a canon compared to some other Sitka/Rosewood dreads I have played. Can that experience really be due to Adirondack spruce or am I falling prey to the "myths" and my ears are hearing what they think they should?
It must have been that guy who writes the cutesy-pie ad copy for the Mandolin Brothers circulars. My guess is that the person that told you that Adirondack spruce is the "best" wood for steel-string tops, is likely to be someone selling an Adirondack spruce guitar, trying to seed a mythology about the material. Or someone impressed by one who was. Be skeptical. Be very skeptical.
Anyone making finger-wagging pronouncements about the inherent "superiority" of one species over an other, is to my sights, likely to be either a faker or a fool. I can tell, because when I began my long journey into this field, I was repeatedly mis-educated by their pat, self-confident pronouncements and many just like them. And usually, it was the more expensive varieties (imagine that!) that floated to the top of the pile. Common, low-cost species were beneath contempt. The only worth considering were the ones whose stratospheric cost and impossible rarity were proof of their magic. No further explanations were given as to what kind of scale these comparisons were being judged on. Just that mahogany was just okay, Indian rosewood was good, Brazilian the best, and so forth. To this day, forty years later I am still unlearning those sentimental myths.
There is no objective reference for beauty. Beauty does not emerge by your knowingly selecting one species and not another. A skilled, experienced, thoughtful maker can make a beautiful instrument from any species.
Beauty can emerge, but from the synthesis of a hundred values and senses acquired slowly, almost as a gift--as a reward for persistence.
Given that, which then is an efficient learning path for the luthier?
1- Give up your search--and don't fall for--quick tips that claim to achieve beauty. Disbelieve anyone claiming that "Mahogany will sound warm, Rosewood will sound clear." Run from them like the plague. If someone tells you if you do a certain thing on a guitar it will make it "sound better", ask how specifically they came to that conclusion, and what evidence they found persuasive. Then don't wait for an answer.
2- The greatest illusion of all: "tonal manipulation." Give up the illusion that anyone can teach you guitar "tap-tones"--however they're defined--and that you can objectively use them to make a guitar sound "better". They can't teach you: they don't make the sound "better." The system is too complex to be reduced to tap tones. Don't tune the parts to any note. Don't sand in any spot until its "right." Don't carve braces so they look like a cartoon of the Alps, thinking that will achieve beauty. Don't think that the secret to this certain guitar is that it's braces leap over and tunnel under each other. It isn't. The guitar's secrets are not obvious or easily revealed. The tantalyzing prospect of direct manipulative control over guitar tone is mythical, illusory.
3- What is a guitar, essentially? No, it's not a wave-transforming apparatus. It's a cultural artifact. And what is the highest calling of a luthier, essentially? No, not some eccentric kind of inventor, forever plotting how to invent a better mousetrap. By my sights, the highest calling of a luthier is more properly a skilled duplicator of a high cultural value, whose purpose it is to try to elicit from a long-familiar cultural form a long-familiar sound--a sound prized by the culture's collective ear.
Different culture--different idealized form, different prized sound. The Chinese pi'pa sounds like to us like somebody slapping a rubber band against a cigar box. But it sounds like heaven to the Chinese. The master pi'pa luthier's calling is to get that nasal twang just right.
The guitar's sound is a largely a consequence of its form. What follows is that as you change its form, a different sound emerges. Cultures change its preferred, prized instrument sound---with its iconic instrument's attendant change in form--very slowly, like the movement of a glacier. Heed this advice, ego trippers with the delusion that the culture will beat a path to your hastily-contrived novelty guitar form.
4- What to actually strive for is not ineffable beauty. Therein lies madness. What to strive for are achievable, objective goals: accurate pitch, comfortable action and playability, precise neck geometry, clean workmanship, tight glue joints--the result of sharp planes and chisels; precise measurement and attention paid with brain in gear. If you apply this to the familiar, culturally-derived forms, the guitar's culture will reward you. Your guide, then, are the precedents and solutions set forth by and found within the work of the various extraordinary makers that came before--makers already prized by your culture who, by the sheer variety of successful solutions to the similar problems, teach that there are several good ways to make the same delicious pie.If you do this you will likely be, as I was--surely and eventually--rewarded with the ability to make beautiful guitars consistently. No, I can't tell you how long it will take. It took me about 10 years when I noticed that I had reached a routine and mind-set that was working. Then another 10 years to learn to do it with acceptable efficiency and effortlessness. Then a 20 years voyage towards mastery. You may be able to do it sooner, I don't know. I'm a slow study.
And 5- Avoid the inevitable mystification of the craft. True, this here is a realm of deeply-ingrained iconic and historic cultural values--very strong medicine. But keep it under control. The mystique may have driven you into the craft--fine. But you soon best cast it away, because it is an impediment to attention to the doable, knowable. Others may think this is inspired, shamanic activity. You'll find that it is complex, demanding, often frustrating activity. But what it really is, is real-world problem solving. Given ample time, it is mastered by reason, attention, introspection and persistence. Then, mystically, the beauty begins to appear on its own.