Number of pieces of wood....
It's a tough one to quantify on a number of levels, which makes it a confusing and easily misrepresented factor. The short answer is, like everything - yes, it matters. BUT! How much does it matter? Are you ears good enough to tell? How many pieces does it need to be before you can tell? If you can tell, is is worse or just different?
Lots of people insist that they can tell, but I think most of them are dreaming. The number of people in the world who have done actual back-to-back testing with the same piece(s) of wood is probably less than have been into Space. Speculation and low-sample anecdotal evidence can only get you so far before you're just plain guessing.
Take a look at some legendary tone machines - '59 Les Paul, '63 Strat, '58 335
How many pieces is the body on each?
LP = 3
Strat = 3
335 = 16
What about the necks?
LP = 4
Strat = 3
335 = 4
"Oh, but you can't count the bookmatched top or the fretboard or the truss rod filler or the laminations!!"
Why not? They all get slapped up with glue. They all present an interface to waves moving within the structure.
So, feel free to consider the number of pieces your guitar is made of, but do compare apples with apples. Almost none of the most famous tone machines support the theory that you need a one-piece body.
My preference is generally for a two piece body for stability and symmetry in the final product, cost and availability in the pre-production stage.
Leo Fender originally specified three piece bodies with the glue joints away from the core of the guitar. I think that's a perfectly valid idea too.
One-piece bodies are great, but they have drawbacks. Timber over 250mm wide is hard to get and much more expensive. When you can get it, the chances of it being the required quality or cut is very low. The chances of cupping or splitting goes way up. The time required to ideally dry and season doubles. I'm lucky to have found several stocks of wood for one-piece (anything) bodies and necks that meet all the usual criteria, but that doesn't mean I'm going to use it all on Radians. There are some one-piece Radians around, but most are two or three piece and a couple four piece. I wouldn't bother going more than that because for one thing I don't need to, because laminating lots of pieces is a pain in the butt, but also because there's always some golden-earred genius who will make something of it, whether there is something to hear or not.
Next time you see a lovely Les Paul with a one-piece mahogany back, ask yourself, is it one piece of the only 350mm wide scrap stock they could find? Or would you be better off with a three-piece back of actual decent wood?
Ever wonder why Gibson drill lightening holes in most of their Les Paul models now? It's because light one-piece backs are so hard to get that they're not going to waste them on standard production models when they have people queuing up to buy custom shop models at triple the price. They use the heavier, less desirable wood and drill all the weight out of it. While everyone's wailing and gnashing their teeth at horrible old Gibson and their cheapo chambering tactics, some of the most desirable corksniffy boutique luthiers in the whole World do exactly the same thing. Gustavsson and McInturff, for example, and they charge MEGABUCKS and rightly so.
If anyone wants to fund it, I'd be quite happy to build some test bodies to put on trial
