The lyrics I remember go:
Uptown, downtown, Buster Brown
Whatcha gonna do when the rent comes round?
Whatcha gonna say? Whatcha gonna pay?
Whatcha gonna do on Judgement Day?
There may have been more to it, but that's all I remember. Anyway, I tracked down the original by the expedient of googling for the second line of the song instead of the first, and it turns out it's a bastardized version of a racially-dubious* minstrel show song from the late 19th century whose chorus starts, in at least one version:
Oh Roofus Rastus Johnson Brown
What ya gonna do when the rent comes round.
What ya gonna do? What ya gonna say?
What ya gonna do come the Judgement Day?
Thread on mudcat.org where I found it.
It'd be interesting to know when the first line changed to "Uptown, downtown, Buster Brown."
* Well, ok, that qualification is probably unnecessary given "minstrel show."
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