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Subject line sums it up i think- do you feel a strong relation between the former and the latter?
I think it's a pretty significant question, meant mainly in regard to top wood. I'll save my
opinion for later- if there is a response..

I have been building guitar for over 10 years now. I don't think you can tap a top and know what it will sound like on a guitar , at least not a steel string. Look at what a top is and what a guitar is. Until the forces of the guitar are applied to that top at best all that tapping will tell you is that your bracing may be loose. You have rotational forces , compressive , and tensional forces all acting on the top from the strings and the resultants of applied force , you can't replicate this . You need the thing glued and strung to know what it will sound like. In my early years I thought I could hear something , but I think it was tinitis.
I use deflection testing for stiffness , and I will tap the top when I am finished with gluing in braces but only to see if the braces are tight and that the top isn't dead. Just my 2 cents. The funny thing is that CF Martin never taps a top either. After building 100 guitars I think I have my sound dialed in pretty well. Experience is just a way of making better choices after learning from bad ones.
The laws of physics apply to guitar tops , everything happens for a reason. With a top having so many parts , you must control the variables. When you look at the top , in most cases you have 19 parts , the braces, bridge , the plate and pins , that all will affect the top in one way or the other. This is where building goes from science to art. The builders style influences the end result. I am more worried on gluing and joinery techniques , as this is key for a good result.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I've built about as many as John has, although it took me longer, and I'm going to disagree, sort of. I think there is a correlation between tap tones and the final sound, but it's not a simple one. In other words, if you made two tops with tap tones at the same pitches, they could sound quite different, and two with different tap tone pitches could sound more similar. I think the absolute pitch of any single top tone is not very important, so long as it's within reason. I think the relationships between the pitches of the tap tones in a particular top might tell you more. I think that the -quality- of the tap tones tells you the most, and I find that to correlate pretty nicely with the shapes of the Chladni patterns. Clear, ringing tap tones tend to come from clean, well-formed mode patterns, and yeild good sounding guitars in my experience.

There's a simple reason why Martin doesn't use tap tones: they can't do it economically. They have good designs, use good wood, and reasonably careful production quality control, and they make a pretty consistent product given the variability of wood. It just shows you that if you don't need to match some certain sound spec, you don't need to do much else. Every guitar they make will be somebody's 'Holy Grail', and if they can find that person enough of the time they'll stay in business.

I'm often building for a particular person, with a specific notion of what they want. If I don't get pretty close I lose the sale, and I can't afford to do that very often. I need some way to make the guitar do what I want it to do, and the simpler and less time consuming it is, the better. I feel that a couple of hours of messing with Chladni patterns or tap tones per guitar helps me get what I want. In a production setting man-hours are the most expensive input; if Martin did what I do on every guitar their prices would be through the roof.

John is certainly correct in pointing out that the leap from the 'free' top to one glued down to the rim is a big one; it's the weak link in any 'scientific' defense of tap tone tuning of any sort. You simply can't demonstrate that a given tap tone or Chladni pattern 'becomes' a particular resonant mode on the completed guitar. The math is too complicated, there are too many variables, and 'good' sound is subjective. But I don't think anyone will go so far as to say that the way the top works all by itself has nothing at all to do with the sound of the completed instrument. Just because we can't demonstrate the linkage in some simple deterministic way doesn't mean it isn't there.

Thanks for both of your though-provoking replies, John and Alan. I need to think about this
more before saying something silly. -Carey

Someone doesn't listen to the resonance of their guitar while building it?
That is half the fun of building!
Here is my tapping schedule:
As I'm going thru the stacks picking tops and back and sides sets.
After the top and back is joined.
While carving the top and back bracing to it's finished dimensions, lots of tapping here, and lots of fine carving after listening to the tap resonance.
As I am sanding the whole body, just prior to purfling and binding. Here I am sometimes thinning the edges of the top.
As I am finish sanding, 320 grit, prior to finishing. Last chance to go too thin!

All these bonking sessions have a huge influence on the sound of my guitars.

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