What the heck, as my real name has been used here in a post above, I will jump in.The information quoted to Ulf above comes from an Affrican Akonting player named Daniel Katta (SP?). I heard him present his evidence in Lexington Mass last fall. He is well researched and well read. When you look at the physical structure of the akonting vs the Khalam and molo, this makes the most sense notwithstanding previous claims. The akonting is in fact round and the bridge sits directly on the head, not on the dowel as in the khalam. With the exception of tuning "pegs" it is made almost exactly like an early gourd banjo.
So far as Sweeney goes --- I hope that I am not so dense as to miss the post above as humor. If it is not meant as humor (which means I am that dense) then I must appologize. Sweeney, of Va.learned banjo from the carrage maker slave of Dr. Walker. Dr. Walker owner a nearby plantation and in fact was the very doctor that brought Sweeney into the world. This is how Joel got the middle name Walker. Accoding to family histories, Joel made two banjos out of gourds in the style of the local slaves. His mother destroyed the first when she discovered that the skin head was from a family cat! She found the second but relented for fear that even more cats would meet the same fate. There will be a new biography of Sweeney comming out soon by Bob Carlin. He has gone as far as England to research Sweeney's life accurately. When it comes out, anyone interested should read it. He died about the time of the Civil War. His brother Sam raod with JEB Stuart in the Confederate Cav. and died in 1864.
Banjos of Sweeney 's time and later were tuned one of two ways (commonly) from the first string down a f# d g D and the second tuning was the same only one full tone higher. These tunings are shown in all of the period instruction manuals from 1848 ( Jumbo Chaff [Ellias Howe]) to the to 1872 (Frank Converse ). Frets were not common until after the Civil War (about 1875 from currect reasearch) BUT in 1859, the Buckley's manual encourages the use of frets on the banjo. The math used to place the frets however was fafulty and the early fret jobs require a small fret under the 1st string only 1/8 inch up from the real 2nd fret. Only two or three known examples of this fret work is currently known. Most banjos from the period are indeed frettless.
On the subject of the banjo in the Los Angles County Museum, it was made by Sweeney from a commercail hoop made by William Boucher of Baltimore MD. It is a left handed banjo made for Sweeney's niece who was left handed. Sweeney was right handed.
Just a quick note also on tack heads. The tackhead banjos can be found in sales sheets as late as the 1880's. These were cheep beginners instruments. The early tackheads used mostly small tacks (brass) or even wooded pegs similar to thoses used in shoes of the period. There are several gourd fiddles that are still around useing that method. Most of the early tackheads I see use plain headed tacks of brass and just a few in steel.
For more information get the book "America's Instrument: the banjo in the nineteenth century" Univ. of NC press 1999. There has been quite a bit of new research in the last few years, the old myths are being replaced with new and correct history backed by well documented souces. If your history is more than three of four years old.... it is outdated to one degree or another.
BTW, my data base and researchis open to anyone who wants to travel to my shop. Don't taske my word for it, look at the evidence for yourself. Besides it's lonely in my banjo shop, I need the company!