Does Alicia Keys Have A “Family Secret” She’s Protecting?

Superstar Alicia Keys was scheduled to appear on an episode of “Finding Your Roots” with Dr. Henry Louis Gates, but apparently she had to renege on the appearance after her grandmother told her a family secret that she didn’t want exposed. Alicia did not reveal the deep dark family secret that is keeping her from doing the show. She pretty much just pulled out with no explanation.
According to Dr. Gates, Alicia initially accepted the offer to appear on the show, but then backed out after talking to her father’s mother. Peep what he said about the issue below:
“Alicia Keys, who I love as a friend of mine, agreed to be in the first series, and as you know, she’s mixed. We need as much information as you can give us. Like the names of your parents, where they were born, grandparents etc., whatever you can give us. It makes our job a lot simpler right? Her Puerto Rican grandmother said, ‘Baby, you can’t be in the series. I can’t tell you why, but you can’t be in the series.’”
Sounds like Alicia’s grandmother was not trying to air out the family’s dirty laundry. Wonder what they’re hiding?