Fruitwoods? Did someone say fruitwoods?
Let's start this discussion by pointing out that walnut is a fruitwood...
For solidbodies, pear, apple, etc., are fairly uncommon. _I_ think that the main reason for that is that orchard-grown trees are generally limited in size, and it's not easy to come by billets large enough for body blanks. Also, they generally don't have the bold exotic figure that today's boutique builders look for in drop-tops and backs.
Also, very few major suppliers, like Southern Lumber, carry the species because simple economics dictates that the vast majority of shelf space go to maple, cherry and oak.
Now, all THAT said, pear is quite good as a tonewood. LMI is selling more and more of it as backs and sides to builders who want a lighter colored instrument that isn't maple. It's a decent-to-excellent tonewood that works very well (bends nicely, doesn't munge up your cutting tools, etc.). It's a little blotchy to finish, but if you seal and fill it properly, it takes dyes and clearcoats nicely. I don't know of anybody who's built acoustic tops out of pear, but if I had a properly grained chunk available I'd give it a shot on a classical or flamenco with the expectation that it's going to sound like a slightly compressed cedar.
I seem to recall that apple has been used as an acoustic top wood, with mixed results. Olive has recently been used for backs and sides, with good-to-spectacular results. I haven't come across anything done from orange, again probably because of the size issue. Orange trees simply don't get to be all that big around.
Pecan, otoh, is really cool. Think of it as half-way between walnut and mahogany. One downside is that it's a bit heavy. One upside is that it generally has a better tap tone than walnut. Highly figured pecan is kinda rare; it's much like mahogany in that respect.
Alas, none of these are really rigid enough to be used as neck primaries, but olive and pecan could be used as intermediate laminations. Overall, though, I'd tend to use them as hippie sandwich ( Alembic, Inc.) cores, and there only if I were doing a full hollow chamber.
nic