Last but not least a categorisation by Azizi Powell (taken from pancocojams.blogspot.de)

THE MEANING OF "IT'S TIGHT LIKE THAT"
The phrase "it's tight like that" in Thomas A. Dorsey's (Georgia Tom) & "Tampa Red" Whittaker's late 1920s song of that name and other versions of that song have definite sexual connotations. However, there's plausible deniability that no sexualized meaning at all are intended by that title or those verses. For instance, "it's tight like that" could be said to mean something like "That's the way it is" ("It bes that way some time.). Or "It's tight like that" could be said to mean "Times are bad." (as in "Money is tight"). While the first "clean" meaning I suggested might be the meaning of some of the lyrics in versions of "It's Tight Like That", I'm not sure that the second "clean" meaning was ever intended in any of those song's verses. There's no a doubt in my mind that, with the exception of Leadbelly's version, most of the lyrics of the "It's Tight Like That" song are meant to be risque. It bes that way sometime.