I understand that this sentence is difficult, possibly even tortured. Were I to publish it, I would probably rewrite it to something like:
"[A soul song sung by a white woman was] played on rock radio. I believe rock radio would not have played it if the song had been performed by a heavy-set black woman."
In deference to the anonymous respondent, I will remove the which.
"[A soul song sung by a white woman was] played on rock radio. It probably would not have had it been a soul song performed by a heavy-set black woman."
I'm not writing for composition advice, but I do appreciate it. I am asking whether (strictly formally, and strictly the "would not have had it been" portion in an otherwise-unflawed sentence) the construction is syntactically flawed, and, if not, can you give this native speaker the name of the conjugation/mood being used? The answer would sound something like "conditional past perfect", but that (of course) is not the right answer.
A thank you in advance, and if formal grammar questions are beyond the scope of this board, no problem there, and I will thank you and move back to lurking. 