The halls of Pittsburgh's Creative and Performing Arts School rang with the sweet sounds of cello, guitar, percussion and excited young voices yesterday as the school's students put on a musical display of their talents for first lady Michelle Obama and the wives of the G-20 summit leaders.

At times, though, it sounded like a rock concert for all the shrieks and screams, first when Mrs. Obama was introduced to the students by Pittsburgh Public School Superintendent Mark Roosevelt, and later when three well-known musical artists -- cellist Yo-Yo Ma, country singer Trisha Yearwood and singer-songwriter Sara Bareilles -- were brought on stage to perform with some of the students.

The concert followed a mid-morning tour by the G-20 summit leaders' spouses of CAPA's contemporary, multistory building along the city's Allegheny River, just a few steps from the David L. Lawrence Convention Center, where the world's leaders were closeted with President Barack Obama for the two-day summit.

The spouses were broken into five groups, visiting two classes that represent the school's six majors: visual arts, literary arts, theater, instrumental music, vocal music and dance. About 800 students attend the school in grades 6 through 12, although for space reasons, only 250 were selected to attend the concert. Each tour was accompanied by a teacher and a student to explain what they were seeing.

Mrs. Obama's group included Marisa Leticia da Silva, wife of Brazil President Luiz Inacio Lula da Silva, and Carla Bruni-Sarkozy, wife of France's president, Nicolas Sarkozy. They were accompanied by Jackie Hale, a teacher, and CAPA student Laneece Patterson, visiting a ballet studio and the high school's orchestra room. The total visit took about 20 minutes, and Mrs. Obama later told the school's students that her tour "brought tears to my eyes."

CAPA Principal Melissa Pearlman introduced all of the summit leaders' wives, who were standing in the balcony, but it was Mrs. Obama who received the most deafening greeting from the students, who leapt to their feet when she entered the stage, wearing a boldly patterned purple and white silk dress from one of her favorite Chicago designers, Maria Cornejo of Zero, and a wide-studded leather belt.

"You can literally say that the world is watching you all today," Mrs. Obama told the group, noting that the occasion would "celebrate some of America's most gifted performers and some of the hottest up-and-coming young talents in our nation. That would be you."

She noted that "my good friend" Mrs. Sarkozy expressed amazement during their CAPA tour that "in America ... here you have people who can sing, and they can dance, and they can act. Now, she said in France it's not often you get all of those wrapped into one. But she said there's something unique about America's talents where it's just so natural to see all of that talent on display. So you all should be so very proud."

She also praised the three artists performing with the students, noting that Ms. Bareilles' songs were on her own iPod. "Gravity" and "Love Song" have "gotten me through many a day. I love her."

Mrs. Obama also delivered a shout-out to Carnegie Mellon University professor Gregory Lehane, whom she called "a widely recognized director." Mr. Lehane, along with composer Marvin Hamlisch, principal pops conductor for the Pittsburgh Symphony, auditioned students for the concert.

"The arts aren't just a nice thing to do if you have a little time, right?" Mrs. Obama told the audience. "It's not just a hobby, although it can be a very good hobby. It shouldn't be something you do just because you can afford it."

She and her husband "believe strongly that the arts aren't somehow an 'extra' part of our national life, but instead we feel that the arts are at the heart of our national life."

The concert's musical highlights were nonstop: the CAPA choral ensemble sang a song welcoming the G-20 summit leaders written expressly for the occasion, accompanied by Mr. Ma's warm cello, including the line "We're glad you came and hope things will change." Later, Mr. Ma performed Camille Saint-Saens' "The Swan" accompanied by Jason Yoder, a CAPA junior, on percussion -- whom Mr. Ma introduced as "my buddy."

The students also seemed truly thrilled by Ms. Bareilles, who easily got the most raucous reception after her performance of "Love Song," but who confessed to a mild case of stage fright.

"I was doing jumping jacks in the back because I thought I was cold but I'm just really nervous," Ms. Bareilles told the audience, to laughter.

While the program focused on the performing arts, ninth grader Miller Schulman of Squirrel Hill, a student in the school's visual arts department, presented Mrs. Obama with the gift of a Photoshop collage he'd created called "Pittsburgh Transforming." The artwork was chosen from almost 300 CAPA student entries by a jury that included Mayor Luke Ravenstahl and Warhol Museum curator Eric Shiner, among others, said the youth's father, John Schulman.

Mr. Schulman said his son reported that he got "two hugs apiece from Carla Bruni [Sarkozy] and Michelle Obama, who told him, 'Here's my man!' "

Shortly before the concert it was time for a "family photo" of the world leaders' spouses, who gathered with Mrs. Obama in the high school's "Cabaret Room" for a group picture. Last one to arrive was Mrs. Sarkozy, who, after being escorted onto the stage, turned around, saw the photographers and gasped. "Oh my gosh! Hi!" she said to the assembled media.

The group was asked to stand on a short riser for the photograph by the press pool. As flashbulbs and cameras clicked frantically, the women laughed and joked among themselves.

"Tell us when we can stop," Mrs. Obama said, laughing, adding, "Cheese!"

After the CAPA visit, it was off to the Andy Warhol Museum, where Mrs. Obama hosted a luncheon and a tour for the wives of the dignitaries.

The arrivals walked past window displays of spinning disco balls suspended above black-and-white photos of Warhol looking through the center of a tambourine and wearing his trademark sunglasses.

Ms. Sarkozy was the only wife who spoke to the media there.

"I think I wish I could stay a little longer," she said about her Pittsburgh visit. "Because we only stay one-and-a-half days, but I think it's beautiful."

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