ST. LOUIS, MO (KTVI-FOX2now.com) - St. Louis' push for the Democratic National Convention in 2012 went into high gear Thursday night. With a committee charged with picking the site in the city, organizers put on a downtown concert with rock and roll legend Chuck Berry and Grammy Award winning rapper Nelly. But the crowd was the star. Kiener Plaza was packed with people already signed up to volunteer for the convention if it comes here.

It is the result of an unprecedented grass roots effort to lure the convention to St. Louis. The usual comparisons of hotel rooms and venues between perspective cities is also taking place, and organizing officials here say St. Louis stacks up very well compared to rivals Charlotte, Cleveland, and Minneapolis. But they feel the additional strategy of energizing the population will put St. Louis over the top.

"We've been doing a lot of social media and what we found was what these people are doing is they're all raising their hands and saying how can I help," St. Louis DNC 2012's Mack Bradley said. "What can I do? How can I get involved? The purpose of tonight is to give people an outlet to do just that."

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The one thing Bradley could not talk about was the group in town to "kick the tires" on St. Louis. Politicians have confirmed their presence, and many joke it's the worst kept secret in town, but the organizing committee signed a confidentiality agreement forbidding them to talk about the visit.

They would, however, talk about the job of the group making the choice.

"This is a small group of people who have very technical skills who really roll up their sleeves and do some real work digging into our bid to see if we can do everything we said we can do," Bradley said,.

The crowd of would-be volunteers roared with approval during Berry's set, and came to life even more when Nelly, billed as a surprise guest, took the stage. Both performers led the crowd in chants of "STL 2012" throughout the night.

Fans on hand say the concert is a bonus, but they're most excited about what the Democratic Convention might bring to St. Louis in two years. There are hundreds of millions of dollars at stake according to organizers, but volunteer Craig Johnson says it's more than that.

"Prestige mostly, and some money. But I mean that's prestige to have it here," he said.

Landing the Democratic National Convention two years from now would be more than a feather in the region's cap. The convention could produce both economic benefits and publicity that last well beyond the week's events. Civic, political and business leaders spent the day showing off the region's assets.

Leaders of the Democratic party spent the day checking out venues and looking at services a large political gathering needs. The tour for DNC officials was done quietly. But underneath there is a building sense of excitement.

While other cities are just showing off the hotels and buildings St. Louis holds a concert. Organizers and volunteers hope good old fashioned excitment will carry the day. The concert is packed with volunteers. Every one of whom has signed up to volunteer for work at a St. Louis Convention.

"We've been doing a lot of social media and what we found was what these people are doing is they're all raising their hands and saying how can I help? What can I do? How can I get involved? The purpose of tonight is to give people an outlet to do just that." said Mack Bradley St. Louis DNC 2012

From top police brass to the Missouri department of transportation and East side leaders the region made sure everyone was on the same page.

"we have the experience in handling big events. We've handled the All-Star game, we've handled Final Four. We even had an event where we had 80,000 people. About 80,000-100,000 people showed to support candidate Barack Obama when he came to St. Louis and had an event on the Arch Grounds ." said St. Louis Mayor Francis Slay

The old Kiel Opera House has been empty and deteriorating for decades. Now, the facility is being renovated and will open as the Peabody Opera House well before the convention.