Re: Duke Ellington's use of the phrase "Black and Tan":

To African Americans that phrase means [or rather "meant" as I don't think it's used anymore] Black people who have dark skin color and Black people who have light skin color i.e. "Mulattos"-another referent that has been retired. For at least 30 years, the colloquial term "mixed" has replaced the referent "mulatto". My experience has been that the term "mixed race" is more often used outside Black communities than within those communities.

Given the riveting historical information about "Black & Tan" as the referent for the British regiment in Ireland, and the information about the "Black and Tan" drink, I find it ironical that another colloquial referent that Black Americans {if not others} use for children of Black/non-Black ancestry is "half and half".