This may seem an odd idea, but I have been contemplating the function of one for awhile now...mainly to achieve a tone between the spectrum of a guitar and a banjo. What I intend to do is make a removable sounhole banjo head that can slip in and/or out of the larger D-Hole size of a Maccaferri. I realize how difficult this may be to accomplish, but I think I can work out a usable design that would fit smoothly over the soundhole.
Now for the big question (for any experimenters or luthiers)...will this achieve the tone of a banjo somewhat? Or, alternatively, will I end up with with an odd looking and sounding guitar?