ST. LOUIS • Supporters of landing the next Democratic National Convention hope the man who made "Johnny B. Goode" was able to dazzle party scouts in town this week.

St. Louis is one of four cities in the running for the party's 2012 gathering, with a Democratic site team also visiting Cleveland, Minneapolis and Charlotte, N.C.

Their visit was supposed to be kept under wraps — each city signed a confidentiality pact — but that didn't stop the St. Louis host committee from throwing a concert Thursday in Kiener Plaza featuring local rock 'n' roll legend Chuck Berry.

The original "Brown Eyed Handsome Man" treated the downtown audience — and, presumably, the Democratic site team, though no one would confirm its presence — to a rare outside concert. Berry, a St. Louis native, plays monthly at Blueberry Hill but doesn't make many public appearances.

On Thursday night, he was followed on stage by the city's other musical ambassador, the rapper Nelly.

But it will take more than star power to score the 2012 convention, which brings with it thousands of visitors, millions of dollars for the local economy and bragging rights that last long past the nominations are complete.

The city's Convention and Visitor's Commission says it has already secured more than 15,000 hotel rooms, though raising the requisite funds to host the event — as much as $40 million to $50 million — is made even more daunting by the struggling economy.

Thursday's concert was not aimed at collecting that cash — it was free, with priority given to individuals who submitted their name into a volunteer database. Instead, organizers were hoping that the concert would show off an intangible — community enthusiasm — that could give St. Louis an advantage over the competition. None of the other cities in the running for the convention threw a similar event.

Will it work? "Depends on how well he plays," said Ronnie Reece, a Kirkwood native visiting from Los Angeles.

Berry, 83, did not disappoint. The crowd was treated to a vintage performance that included such standards as "Maybellene" and "Sweet Little Sixteen."

The concert drew a packed crowd of hundreds to the Kiener Plaza Amphitheater with many more watching or listening outside the fences that blocked off the plaza.

The Democratic advance team in town is looking mostly at whether St. Louis, logistically, is suited to host the convention. The group visited Scottrade Center and the Edward Jones Dome on Thursday and is expected to look at another possible venue, Busch Stadium, today.

Tours of the Gateway Arch grounds and Forest Park were also on their agenda.

The concert amounted to a pep rally for the city's bid. Supporters held signs with "St. Louis 2012" and wore shirts that said "Paint the town blue."

"I'm hopeful it will work," Barbara Dozier, a teacher in the Rockwood School District, said of the city's attempt to woo the convention with Berry's help. "Having the convention in St. Louis would be absolutely tremendous. "

The other contenders gave Dozier a reason for optimism. "Look at the competition — Cleveland? Have you been to Cleveland recently?"