“Black Betty” is a 20th-century African-American work song often credited to Huddie “Lead Belly” Ledbetter as the author, though the earliest recordings are not by him. The song was first recorded in the field by US musicologists John and Alan Lomax in December 1933, performed a cappella by the convict James “Iron Head” Baker and a group at Central State Farm, Sugar Land, Texas (a State prison farm). The Lomaxes were recording for the Library of Congress and later field recordings in 1934, 1936, and 1939 also include versions of “Black Betty”.
This version recording from the Library of Congress call number AFC 1939/001 2643b2 on May 10, 1939, performed by Mose “Clear Rock” Platt (vocals) at Hotel Blazilmar, Taylor, Texas.
The origin and meaning of the lyrics are subject to debate. Historically the “Black Betty” of the title may refer to the nickname given to a number of objects: a musket, a bottle of whiskey, a whip, or a penitentiary transfer wagon.
Some sources claim the song is derived from an 18th-century marching cadence about a flint-lock musket with a black painted stock; the “bam-ba-lam” lyric referring to the sound of the gunfire. In the British Army from the early 18th century the standard musket had a walnut stock, and was thus known (by at least 1785) as a ‘Brown Bess’. ( https://en.wikipedia.org/wiki/Black_Betty )
In 1934, John A. and Alan Lomax in their book, American Ballads and Folk Songs described the origins of “Black Betty”:
“Black Betty is not another Frankie, nor yet a two-timing woman that a man can moan his blues about. She is the whip that was and is used in some Southern prisons. A convict on the Darrington State Farm in Texas, where, by the way, whipping has been practically discontinued, laughed at Black Betty and mimicked her conversation in the following song.”
Robert Vells, in Life Flows On in Endless Song:Folk Songs and American History, writes:
As late as the 1960s, the vehicle that carried men to prison was known as “Black Betty,” though the same name may have also been used for the whip that so often was laid on the prisoners’ backs, “bam-ba-lam.”
You can download the original WAV file from the U.S. Library of Congress website here and try for yourself to discern the full answers.