WASHINGTON - The President just couldn't say no: Mick Jagger held out a mic almost by way of command, and soon Barack Obama was belting out the blues with the best of them.

The East Room of the White House was transformed into an intimate blues club on Tuesday night for a concert featuring blues all-stars of the past, present and future - and the President himself.

The surprise performance by Obama came at the end of the playlist when the blues ensemble was singing "Sweet Home Chicago," the blues anthem of Obama's home town.

Buddy Guy prodded the President, saying he'd heard that the president sang part of an Al Green tune recently, and adding, "You gotta keep it up."

Then Jagger handed over the mic, and Obama seemed compelled to comply.

"Come on, baby don't you want to go," the President sang out twice, handing off the mic to B.B. King momentarily, and then taking it back to tack on "Sweet Home Chicago" at the end.

That was how Obama ended the night.

This was how he began it: Obama said sometimes there are downsides to being the President. You can't just go for a walk, for example.

And then there are the times that more than make up for all those frustrations, he said, like Tuesday night, when Jagger, King, Jeff Beck and other musical giants came by the house to sing the blues.

"I guess things even out a little bit," Obama joked at the start of a rollicking East Room concert that was electrified by Jagger and the rest.

"This music speaks to something universal," Obama declared. "No one goes through life without both joy and pain, triumph and sorrow. The blues gets all of that, sometimes with just one lyric or one note. "

King, 86, arrived in a wheelchair but rose tall to kick off the night with a raucous "Let the Good Times Roll," quickly joined by other members of the ensemble. And he followed with "The Thrill is Gone."

From there, Obama and his wife, Michelle, were swaying in their seats and singing along to an all-hits playlist including "St. James Infirmary" and "Let Me Love You."

Beck slowed things down with an instrumental "Brush With the Blues," as anticipation built for the arrival of Jagger, who did not disappoint.

The longtime Rolling Stones frontman delivered on "I Can't Turn You Loose" and then teamed up with Beck on "Commit a Crime." Jagger got the president and his wife up out of their seats, swaying and clapping to the music, and picked up the pace with "Miss You," performed with Shemekia Copeland and Susan Tedeschi.