WASHINGTON – The reviews are in, and Mick Jagger sizes up President 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 prodded him to join in on a few lines of “Sweet Home Chicago,” the blues anthem of the president’s hometown, during an East Room concert.

“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, also said he was pleased to see that first lady Michelle Obama was wearing a dress that night that was 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 as 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.

Santana moves to House of Blues

LAS VEGAS – Guitar legend Carlos Santana plans a two-year headlining gig at the House of Blues at Mandalay Bay in Las Vegas, switching venues from his previous home at the Hard Rock Hotel & Casino.

Representatives for the House of Blues say Santana will have a run of shows in May and June, then return in September with the residency running through 2013. Tickets go on sale March 3. Santana says he’s happy to call the venue home, and plans to honor the diversity and culture that the House of Blues promotes as a company.

Part of each ticket sale will go to Santana’s foundation, which supports children’s art, education and health.

J.K. Rowling writes novel for grownups

NEW YORK – Adult fans of J.K. Rowling can rejoice: She has a new novel coming, for grownups.

The kids will have to wait and see.

The author of the mega-selling “Harry Potter” series has an agreement with Little, Brown in the United States and Britain to release her first adult novel, the publishers announced Thursday. The title, release date and details about the book, long rumored, were not announced. A neighbor of Rowling’s in Edinburgh, author Ian Rankin, tweeted Thursday that he thinks Rowling has written a mystery novel.

Her seventh and final Potter story came out in 2007, and in recent years the British author has said that she was working on an adult book and on a Potter encyclopedia. Rowling’s Potter books broke sales records around the world.