as others have said "black girl" gives it a whole other level of detail ... if you do believe there are references to lynching, the lines about the dead husband make a lot more sense ... even then, just knowing this detail about the "girl" and what kind of conditions she'd be living in makes it a lot more affecting
I recommend watching a movie "Birth of a Nation" It was made at the height of white paranoia and fear of emancipating the slaves. It gives a insight into the blues of the times and message or import of the music made under the dark clouds of Jim Crow and the vile acts of the times. Like "Strange Fruit" (Billi Holiday) the import of this song is about lynching. The black girl isn't out cheating, she's swinging from the pines.Imagine her shivering like the branches and leaves. Her man (Daddy can refer to husband or partner) has been decapitated (which can happen when hung) and his body hasn't been found. When you change the lyric to "My Girl" the import of the song can change also, but I believe that the lyric was originally changed to make it marketable to a white audience. The beautiful thing about allegories is that perhaps there isn't a single correct interpretation, however I believe the song is of a loved one (mother or father) asking the deceased girl "What happened??" and the spirit of the poor girl is trying to reply.
One can only hold all blues and jazz artists of those times in awe. They were brave people and the legacy they gave the world was the most beautiful.
I apologise now if I have offended anyone.
Leadbelly actually had two versions of In the Pines; "Where did you sleep last night?" meant for white audiences and "Black girl" meant for black audiences. In "Where did you sleep last night?", the lyric was 'My girl' while "Black girl" replaces the lyric with... well, 'Black girl'.
I make this comment, because people seem to think Kurt Cobain changed the lyrics when: 1, the original's writer is unknown so 'in the pines' has had several versions over the years (some being completely different from one another), and 2, he was covering the Leadbelly rendition meant for White audiences (which is the more common one).