First Lady Michelle Obama attended the concert with a group of friends and, of course, Secret Service agents.
"She was an invited guest of the artist, although she bought her own ticket," said Pier Six marketing director Brandon Linton.
The First Lady was slated to greet the R&B singer, who has performed at the White House, before the show.
Obama was seated just as the lights were dimmed and the R&B singer took the stage, so most concertgoers didn't even notice the wife of the leader of the free world was in their midst.
The party did not sit front and center, but in towards the middle of the audience, according to Linton.
"It was actually pretty cool to see how down to earth and normal they were," he said.
This isn't the first time the First Lady has caught a concert in Maryland. In March, Obama and a few friends -- including Dr. Sharon Malone, wife of Attorney General Eric Holder -- attended the Rachelle Ferrell concert at Rams Head On Stage in Annapolis.