Instead of taking typical famous person transit, Jay-Z opted to ride the subway to one of his recent concerts at Brooklyn's Barclays Center. What happens when such men walk among mortals? They run into people like Ellen Grossman.
Grossman, 67, the now-famous woman on the subway is an artist and longtime New York resident; like Jay, she was born in Brooklyn.
Of not recognising him right away, she said by phone that, "In general I have poor face recognition unless I know someone really well. I was aware Jay-Z was famous and existed, but I didn't know how famous."
Since her celebrity sighting, she's been doing her recon: checking him out on Wikipedia, looking at his Life + Times website.
"I've become much more aware of what he's done and who he is," said Grossman. "And as I checked him out, I realized, how embarrassing that I didn't know who he was! There were all these photographers and a crowd of happy people around him, and security people. So it sort of dawned on me as I was looking around that he was someone famous."
She noted that before he started speaking with her, he was looking a bit "stressed" on the subway platform. "And when I said, 'Are you famous?' he looked kind of relieved... that it was a safe spot. Not to imply that his fans were threatening; just overwhelming."
Before Jay-Z entered her car, Grossman said the subway was "sparsely populated," and her first reaction to the surge of people rushing in was that there had been a 9/11-style attack. When she realized the crowd was more pumped than panicked, she thought she'd encountered a flash mob.
Grossman said she considers herself "an old lady," as she has been identified on many a blog this morning. "I was flattered that some people said, 'Oh, she's not that old!'"
In her 46 years in New York, this is her most spectacular celebrity run-in to date, though she did meet Dick Cavett at a lunch counter "a zillion years ago."
Asked if she's got a favourite Jay-Z song now that she's been studying his catalogue, Grossman declined to play favourites. "I can't go there," she said.