Some words - including those words - are absolutely racist; and should be left to languish in the historical record. I suspect you’re only having this out ‘for the sake of argument’ - I think everyone can understand the extremely short shrift - and, indeed, outright disgust and indignation - you would meet with, if you attempted to ‘explain’ your position outlined above to non-white friends, colleagues or neighbours - not to mention singing the song! On which point, you’ve already noted that you’re ‘not much of a singer’ - I’m glad to hear it, as it means this situation is a purely imaginary one. The moderators quite rightly prefer us to not discuss politics, but this is obviously an especially delicate time to be making a defence of the hypothetical ‘right’ to use racist language.