For more than 30 years, Bruce Springsteen's fervent fans have spread the gospel about the E Street Band's legendary concerts.

"You've got to see the show," they tell the non-converted. "You've got to see it to believe it."

Many bands would crumble under that kind of hype, but Springsteen and Co. have flourished.

At each show, skeptical "newbies" file into the audience at about 8 p.m., then walk out nearly four hours later -- often sweat-soaked and hoarse -- ready to spread the word in a grassroots, viral, peer-to-peer marketing that keeps Madison Avenue scheming and dreaming through martini lunches and surf-and-turf dinners on expense accounts.

"You've got to see the show..."

Though all E Street Band concerts create a sense of occasion, veteran concertgoers know a few secrets. When Springsteen plays more than one night in a city, the setlists and performances tend to be looser and more conducive to "magic" than single-night stands, which usually bring a more standard show.

Though the "skeleton" of the setlist generally stays the same each night in a tour -- with blocks of songs played in the same sequential order -- diehards relish the subtle revisions, many of which are "audibles" called out by Springsteen on the stage while band members scramble to get the right instruments and, at times, the right key.

Springsteen usually issues a handwritten setlist to band and crew about 30 minutes before showtime. As a tour progresses and the band locks into a groove, the setlists become more fluid and audibles more common. He has been known to change the opening song moments before the band hits the stage.

As the end of a tour approaches, all bets are off ... and that prospect has Springsteen diehards salivating about Saturday night.

When Bruce and Co. hit the stage for Harley-Davidson's 105th anniversary party at The Roadhouse at the lakefront, it will mark the final show of a tour that began nearly a year ago in support of the album "Magic."

Since the E Streeters visited Milwaukee for a powerhouse show on St. Patrick's Day at the Bradley Center, the band mourned the death of organist Danny Federici, who lost his battle to cancer, visited Europe early in the summer and returned for a handful of dates throughout the states that have been loose, rollicking and filled with surprises.

Before a concert in Norway, Springsteen played a song called "If I Should Fall Behind," a song that had not been rehearsed for several years. Guitarist Nils Lofgren told The Asbury Park Press that the band played it in an entirely new arrangement and that "right in the middle of it, without any discussion, he started pointing at us to take solos.

"Bands just don't do that -- that does not happen in front of an audience anymore," Lofgren told the newspaper. "And it's a real honor to be a part of something that powerful, with that kind of history, and with that kind of freedom."

At some point in March, the notion of the "audible" swerved into the realm of audience participation. It was never unusual for Springsteen fans to bring signs to concerts requesting certain songs like "Rosalita" or "Kitty's Back." When Springsteen began honoring requests, the signs multiplied and a ritual was born.

The signs became so popular, Springsteen felt compelled to post a message on his Web site:

"All of us have been enjoying the signs and banners with song requests. And we appreciate that the U.S. stadium shows may loom epic in your imaginations, inspiring grand and vibrant art. Please show respect for those in the crowd whose views of the stage may be blocked by your signs by keeping them to a reasonable size and displaying them for only short periods of time."

The band, which already seemed energized by the new music from "Magic," has enjoyed the spectacle.

"It's something we've never done before," drummer Max Weinberg told the Asbury Park Press. "And it seems to make the stadium experience -- as intimate as Bruce has always been able to make it -- even more intimate. That's what you do in a club. You take requests."

Clarence Clemons agreed. "I like this new thing he's doing: going out to the audience and picking up a sign, and showing it to the band," Clemons told The Press. "Sometimes it's a song we haven't played in 20 years, so we have to go back over the hundreds of songs that the band has on file, in their memories, and grab one of them."

Given the circumstances surrounding Saturday -- the Harley-Davidson theme and the final night of the tour -- Springsteen message boards are abuzz with setlist speculation.

What will the signs say in Milwaukee?

At previous Brew City shows, many signs asked Springsteen "Are You Loose?" -- a reference to the famous "Bomb Scare" show in 1975 at the Uptown Theater. (The hall was cleared for two hours because of a bomb threat, the band retired to The Pfister Hotel bar for cocktails during the break and, upon returning to the stage, Springsteen repeatedly quoted the bartender, who asked the band "Are you loose?")

Some fans are wondering if he'll open the show with "Born to Run," usually held until the end of the show, or a cover song like "Born to be Wild," or the song "Gypsy Biker," from the album "Magic." Perhaps a version of "The Ballad of Easy Rider?"

What Springsteen song or cover are you dying to hear on Saturday? Use the Talkback feature to let us know.