Blues songs are about sex. Especially Chicago Blues songs, because Chicago Blues was being played in nightclubs in the presence of woman. The sexual references, by and large, are the singer singing to the women present at the performance. Smokestack Lightnin', the song, is chock full of sexual references. For one thing, the "Midnight Train" is all the woman the singer will be having sex with that night. The recurring chorus is huge in this respect, the howl and then "why don't you hear me crying?"--this, I know, because I sing this song regularly, and the women in the room often don't realize the song meaning, and there I am, singing "why don't you hear me crying?" life as big as art. As the verses go on, the statements become more overt, especially, "stop your train, let a poor boy ride" may literally be asking the working girls for sex for free--I had taken a neighborhood young thing to the show, sang the song, and got propositioned on the ride home--videoing it for the purpose of selling XXX sex videos was nearly immediately suggested. The lyric is "Litty itty bitty boy done me wrong" means erectile dysfunction. surprised this is obscure, but for me, hell I've sung the song 200 times or more