Rather than spend a lot of time and effort reinventing the banjo identification page, why don't I just send you to one of the most valuable fretted instrument sites on the internet? You need to know about this site, anyway.
The site is Frank Ford's Frets.com. Frank is a very experienced luthier, who really knows his stuff.
For his section on banjo anatomy, go to Banjo Anatomy. Check out his other pages, too, but remember to come back here for all the late-breaking news and arcane banjo setup secrets.
