In Thomas Jefferson’s Notes on Virginia (1788) he says that the instrument we know as the Banjo is “proper to the blacks, which they brought hither from Africa, and which is the original of the guitar, the chords being precisely the four lower chords of the guitar.”
But your dictionaries tell that banjo is probably a African American corruption of the far older bandore, known ” to the ancient Greeks as pandoura, a musical instrument of three strings.
It seems not to have occurred to anyone that both may be right.
The Greeks had contact with Ethiopia, as well as Egypt, from the days of Homer, and might well have introduced the pandoura into such regions of Africa.
