WASHINGTON -- The White House celebrated the heritage of blues music Tuesday with a star-studded concert and a workshop by Michelle Obama, who admitted she can't sing or play an instrument.

"But you can," the first lady told a group of students from across the country who sat rapt as a panel of blues musicians shared their craft. "Remember that you're grooming to be the next greatest something. ... It starts with believing that you can be there."

Hours later, the musicians were to take to a White House stage for the "Red, White and Blues" celebration - the latest in the "In Performance at the White House" series.

Among the headliners: Rolling Stones frontman Mick Jagger.

But it was the presence of blues legends such as B.B. King and Buddy Guy that impressed some of the art form's youngest performers, including jazz musician Troy "Trombone Shorty" Andrews, 26.

"This is a dream come true," Andrews told reporters during a rehearsal break at the White House. "Celebrating the blues with Buddy Guy, B.B. King. They're the legends of the music, and I'm just excited to be here."

So, too, was Jagger. Obama stopped by to visit the performers as they rehearsed Monday, and Jagger spread the word.

"Met President Obama who listened to a few tunes during rehearsal," Jagger tweeted, adding that the president "seemed really relaxed and happy!"

Jagger, who was at the White House with his girlfriend, fashion designer L'Wren Scott, also tweeted that they got a "lovely tour of the West Wing."

The concert comes in recognition of Black History Month. In addition, Obama breaks ground Wednesday on the Smithsonian's National Museum of African American History and Culture, which is to open in 2015 on the National Mall.

The first lady celebrated the timing, noting that the blues "traveled from the Deep South into every part of the country and just about every form of music that we hear today."

"The blues are as deeply American and as deeply human as just about any form of music in this country," she said, calling it an "art form that stirs our souls and helps us rise above our struggles."

Andrews, whom Michelle Obama noted was once "a little boy marching through the streets of New Orleans with a trombone twice his size," said he hoped to "steal a few things from the legends" - and had already picked up tips from Jagger.

"He was in character right away, like he was playing in a stadium," Andrews said of Jagger. "It didn't matter if we were rehearsing or getting ready to do the show, he was right there."

Obama wowed the audience at a recent fundraiser when he broke into Al Green's "Let's Stay Together," and the musicians said they were ready for a repeat.

Grammy winner Keb Mo, who attended the student workshop, joked that Obama would perform three numbers, and that he'd be producing a record for him. The title: "After the second term, now I can finally get my groove on, like it's supposed to be."

Andrews said he was hoping Obama would take up his trombone - but he'd be ready for some vocals.

"If he wants to sing, I'll sit back and back him up," he said.

The White House concert will air Feb. 27 on PBS stations.