ST. PETERSBURGExtra-inning games: Good for baseball fans, mayhem for postgame parties.So when the Rays broke an eighth-inning tie against the Chicago White Sox on June 13, a chorus of cheers went up beyond Tropicana Field's centerfield wall."Once that final out happens," said Brandon Groc, Ruth Eckerd Hall's entertainment manager, "it's going to be organized chaos."Sure enough, when the game ended, a crew of more than 30 cracked open the fence and rolled out a giant stage for a postgame concert by country singer Lee Brice. Many of the game's 20,248 fans — the largest home Rays crowd in more than a month — filed down for a better view.On Saturday, the Rays and partner Ruth Eckerd Hall will host another country star, Kacey Musgraves, in their 70th postgame concert since 2007. For nine years, the concerts have been a bright spot amid hand-wringing over the Rays' attendance woes, drawing tens of thousands of additional fans to the Trop to see acts like the Beach Boys, LL Cool J, Miranda Lambert and Train. The shine might be wearing off. In 2008, concert games drew, on average, around 10,300 more fans than the average weekend non-concert game. In 2014, it was just 210 extra fans. This year, average attendance for concert games is actually lower than it was for weekend home games before the concert series began. But even if concert crowds are down, they remain a big part of the Rays' overall marketing strategy, which is why the team and Ruth Eckerd Hall still pull out all the stops for each one. "The biggest goal is to energize our fans," said Stephon Thomas, director of promotions. "We still want to be one of the leaders in the sports arena in being unique and different."• • •The Rays' first postgame concert came on June 23, 2007. The band: Sha Na Na. The Rays won in front of 24,068 fans, well above their season average. Attendance rose overall in 2008, the year the Rays suddenly turned good. But it skyrocketed on concert days, with seven crowds of 30,000-plus, and one that fell just short. The buzz piqued the interest of other major league teams, many of which have staged concerts of their own, even calling the Rays and Ruth Eckerd Hall for advice.Booking acts begins the previous summer, with Rays employees drafting a wishlist. Ruth Eckerd's director of entertainment, Bobby Rossi, checks who's available and presents a list of his own. Both sides go back and forth on desirability and cost. "Sometimes there's an opportunity that's unique and worth it, and we may go outside the budget a little bit," Thomas said. Over the years, the Rays have tweaked their concert strategy to varying degrees of success. In 2009, the team experimented with concerts on Fridays, but those had a minimal impact. Family-friendly Sunday shows, however, are now a staple, with kiddie acts like the Wiggles, Kidz Bop and Imagination Movers.The lesson: Targeting a specific demographic can yield desirable dividends. So while boomer acts like Hall and Oates and Earth, Wind and Fire are always safe bets, the team has also gone after rappers (Ludacris, Nelly), Latin stars (Gilberto Santa Rosa, Tito Nieves), pop singers (Carly Rae Jepsen, Adam Lambert) and DJs (Afrojack, Calvin Harris).Take Kacey Musgraves. Who's the target audience?"Young female country fans," said Thomas. An October show by DJ Steve Aoki? "Millennials." Hook these fans with a concert, and they might return. Ruth Eckerd Hall, too, benefits from the ability to book a larger act in a unique space like Tropicana Field. It "establishes a history with the artist," he said, which helps keep lines of communication open for future bookings. Musgraves is someone Rossi has tried to book at Ruth Eckerd Hall or the Capitol Theatre, but it never worked out. Saturday's concert will be her first headlining show in Tampa Bay.Rossi wouldn't disclose how much the Rays pay Ruth Eckerd for their services, but said it's not as much as you might think."We probably made more money from (the band) Boston in one night than we would the entire season," he said.Thomas said the concerts do generate revenue, which is the ultimate goal. "But for us, it's a little bit more than that."Concert crowds in 2015 are about 44 percent smaller than those in 2008. But attendance, Thomas said, is only one indicator of the series' success. It also generates goodwill among fans, and is one of the reasons the Rays consistently rank high on fan experience surveys."We'd be doing it even if attendance wasn't great, to some degree, just to provide value to the ticket holders," he said. "It allows us to have something to talk about and promote."And, of course, there's the fun factor. Rays owner Stuart Sternberg is a huge music fan; in 2013 the Rays brought in one of his favorite acts, New York indie rockers the Felice Brothers, for a postgame show. "The Rays are always figured as this kind of cheap (organization)," Rossi said. "But when it comes to Stu and (team president Brian) Auld, they're like, 'If we can get them, go after them.' "• • •Concert days at the Trop begin early. For the Lee Brice game, load-in for soundcheck started around dawn so the field could be cleared for batting practice four hours before first pitch at 4:10 p.m. Brice's crew, union stagehands and lighting and sound contractors erected, tested and shut down the stage.For each game, team officials deck out a guest dressing room with food, drinks, custom jerseys and swag like leftover bobbleheads. Artists and their crews are usually given a suite near the right-field pole, though some acts just hang out on the bus. Joan Jett couldn't wait to talk shop with Joe Maddon and throw out the first pitch. Artists like the Goo Goo Dolls have jammed with Evan Longoria, who keeps a drum kit deep inside Tropicana Field. When Brice breezed through the clubhouse before his game, Brad Boxberger got a vinyl record signed. Every now and then, there are disasters — like a 2011 show by Avril Lavigne, who cursed her way through technical difficulties, making national news and prompting an angry tsk-tsk from the team.There have been near-misses. Willie Nelson was all but booked for Memorial Day weekend before a last-minute schedule conflict forced the deal into thin air. For years, Rossi has tried to book the Doobie Brothers, Steve Miller Band, Sheryl Crow, Heart and Billy Idol. Superstar DJ Diplo, whose song Revolution the Rays licensed for this year's Rays Up marketing campaign, couldn't do it this summer, but is a possibility for 2016. And then there's this: "We had Kiss confirmed last year," Rossi said. Yes, that Kiss.The band wanted pyrotechnics — usually a roadblock for an indoor show on artificial turf — but all parties figured out a less flammable solution. A deal was in place before another promoter, who had them booked for another nontraditional event in Orlando, said the gig would've conflicted with his.The good news, Rossi said, is that Kiss had already approved every technical detail of a Trop show, which should make booking them again that much easier. Gene Simmons and Paul Stanley in the outfield, screaming Rock and Roll All Nite beneath a glowing amber dome. Who wouldn't buy a ticket for that?