Something like that.
If I were at DD's party I'd probably look at him and think it in poor taste -- whether or not I've heard of Rick James -- but I certainly wouldn't say so to his face. "Blacking up" is not necessarily racist, although it has strong historical connotations from a time when it wasn't always used in a respectful way. So in that sense I agree that it's in bad taste, ill-judged, and please please please think about this before you go and do it.
But that's different from being inherently racist. It's also possible to find the middle ground, where you mean well while doing something that doesn't come across that way, and I think people ought to make more allowances for that.
So telling you that you are racist to your face just feels wrong to me. Especially if it was someone who is only getting offended on behalf of somebody else.