Naemanson -

Some of the guys who make things like roof arches for churches do still bend wood sections up to about 30" thick, although most laminate thinner stuff - 2 to 3 inch plies.

Unfortunately, my garage - and I suspect yours - just doesn't have enough room for the tooling needed.

Anyone who wants to do a bit of trial and error can probably work up to 1/4 inch thick and have fun. With a bit more concentration, 3/8 inch thick can be done at home with a pretty "casual" setup. Beyond 3/8 inch, with most wood, you're into industrial strength - or you're really a fanatic about proving a point.

I have "straightened" a 2x4 on a couple of occasions, but it's a different sort of thing than making an instrument.

John