I whittled and sawed and drilled this one-string banjo, else one-jo, or else really just a coconut monochord. The monochord is a right old instrument, being as it is - among other things - the tool with which Pythagoras investigated and laid out the principles of integer ratio consonance in sound.
The tuning peg, bridge, and bridge peg are all whittled from some nice dark walnut wood. The body is a coconut half (natch), and the neck is some worthless ply that gave me splinters throughout construction (I think the veneer was the main culprit). The neck intersects the body twice, and there is no gluing involved - the parts are just held together by the friction and tension inherent in tightening the string (a 12 gauge Ernie Ball). All surfaces were finished with a blade.
Coconut shell is pleasing material to whittle; similar to a peach pit only darker and perhaps a bit softer. It is similarly free of grain and has a lot of potential for figuration I suspect - poor man's ebony; black bone.
Sonic considerations. The bridge is rather heavy, and is at present attached to the neck; this could certainly be improved upon. A lighter bridge and some sort of membrane or sound board would increase the volume. I have a bit of paper in there at the moment which amplifies things - who knows why... The tone is good though, and it has a great deal of sustain. In terms of playing the little thing, I am using a pebble to "fret" it, in a similar style to the berimbau player, and knocking out pentatonic airs.
Time: four hours
Beers: two "Moretti"