WASHINGTON >> The reviews are in, and Mick Jagger sizes up President Barack Obama’s singing of the blues this week as nothing short of "courageous."

The Rolling Stones frontman said Thursday the president did "very well" when bluesman Buddy Guy successfully prodded him to join in on a few lines of "Sweet Home Chicago," the blues anthem of the president’s home town, during an East Room concert earlier in the week.

"I thought he was courageous, because there was some element of reluctance," Jagger said, adding that "it was a hard moment for the president to get out of."

Jagger, in a phone interview with the AP, also said he was pleased to see that first lady Michelle Obama was wearing a dress that night designed by L’Wren Scott, his longtime girlfriend, who had a front-row seat for the concert.

Jagger, 68, said he’s never been invited to play at the White House before — or for any head of state — and he rated it a "surreal gig experience."

"I loved it," he said. "It was really unusual, surreal, and strange, but very enjoyable. … I went out there and I tried to put out my best."

What’s next for Jagger? He said he’s on a minivacation on the East Coast with his kids, and they were heading out the door to play soccer.

But will the Stones get together this year for a 50th anniversary tour?

"I hope we certainly do something," he said. "It would be very appropriate, I think, and I look forward to doing something. But nothing is yet booked."

Jagger and other blues greats played the East Room on Tuesday as part of an "In Performance at the White House" concert that will air Monday on PBS.