When Twenty One Pilots came onstage in their undies this month to accept a Grammy for their huge hit Stressed Out, many viewers probably wondered: Who were these weirdos, and how on earth did they get here?The pop/rap/rock/punk/reggae/theatrical/everything bagel of a band from Columbus, Ohio, is, improbably, the hottest alternative act in America. Singer/multi-instrumentalist Tyler Joseph and animalistic drummer Joshua Dun have gone from complete unknowns to festival headliners who sell out arenas coast to coast. And it all happened seemingly overnight.Here in Tampa Bay, however, fans can say they saw it coming.Thanks to early and ardent support from local alt-rock station 97X (WSUN-97.1 FM), this has long been one of Twenty One Pilots' strongest markets outside their home state. Over the past five years, the station has played hits like Stressed Out, Heathens and Ride some 15,000 times, said director of branding and programming Dan Connelly, making 97X "the No. 1 spinner of the band in the country." In one recent seven-day span, 97X played Twenty One Pilots 169 times — a pace of once an hour."Nobody ever gets tired of it," said 97X host Danielle McBroom. "I've never picked up the phone to someone who's said, 'You're playing too much Twenty One Pilots.' It's never happened." So how did Twenty One Pilots get so huge, so fast? It's a long story. But local fans were there from the beginning. Their sold-out show Tuesday at Amalie Arena will be their 10th in Tampa Bay. Let's flash back five years to see how they got there.April 13, 2012: USF Bullstock, TampaTwenty One Pilots barely warranted a mention in the build-up to the University of South Florida's annual spring concert, headlined by Jack's Mannequin and Cobra Starship. But to some, the unknown openers stole the show. "Checking Twitter and Facebook the following day revealed the group had won several new fans," wrote a reviewer for USF's Oracle, "with more than a few fans proclaiming they had outperformed Cobra Starship." The duo acknowledged the love on Twitter, writing: "USF is awesome and we can't wait to come back to Tampa."Dec. 1, 2012: 97X Next Big Thing, St. PetersburgTwenty One Pilots had just signed to Fueled By Ramen, the Tampa-founded label that launched bands like Fall Out Boy and Paramore, when they were booked as the first national act at 97X Next Big Thing in Vinoy Park. "That was the first radio show they'd ever done, and that was the first time they'd ever been called a 'national'," Connelly said. The show fell on Joseph's 24th birthday; they'd celebrated the night before with a pizza party on the pool deck of the Hilton St. Petersburg Bayfront. Despite playing at 11 a.m., their anything-goes stage presence was undeniable right away, especially when Joseph leaped 10 feet from the scaffolding to the stage during Car Radio. "I think we all watched that show," said former 97X program director Michael Sharkey, "and went, Oh, wow, there's something very special with these guys."March 23, 2013: State Theatre, St. PetersburgThanks in part to their strong showing at Next Big Thing, a horde of new acolytes — a fan base dubbed the Skeleton Clique — packed the State Theatre for a headlining gig in support of their new album Vessel. The show sold out in advance, with fans queuing up early outside.May 25, 2013: 97X Backyard BBQ, St. PetersburgIn 2013, 97X began factoring listener voting into its daily music programming. By May, Twenty One Pilots were the station's No. 1 fan-voted artist, ahead of bands like Green Day and Blink-182. "Holding On To You, Migraine, Car Radio — they were always some of the most voted-on songs, regardless of radio airplay," Sharkey said. As a result, just five months after opening Next Big Thing, 97X brought them back to Vinoy Park for its Backyard BBQ — only this time, they'd graduated to the second-to-last slot.Sept. 29, 2013: USF Sun Dome, TampaAnother Florida date, another sellout, this time opening for Fall Out Boy. By this point, Twenty One Pilots had begun to master the formula that made them so unique. "They're making music that sounds really good in the contemporary mix of what's out there; the lyrics are highly relatable for anyone, especially young people; and they put on a really electric show," said former 97X music director Joel Weiss.Nov. 21, 2013: Ritz Ybor, TampaHere, finally, it seemed like Tampa Bay might be suffering from Twenty One Pilots fatigue. It was their fifth local concert in 12 months, an untenable pace, and it didn't sell out. Can you imagine what tickets to see Twenty One Pilots at a club like the Ritz would go for today?May 2, 2014: Big Guava Music Festival, TampaAt Tampa's inaugural Big Guava Music Festival, Twenty One Pilots were slotted below fellow up-and-comers like Haim and Earl Sweatshirt. But their frenzied faithful packed the Florida State Fairgrounds' Expo Hall to watch Joseph skulk around atop his piano, and Dun surf the crowd on a plank with his drum kit. Once again, the reaction proved telling to promoter Tony Rifugiato, who was working there that night. "There was that moment, being there at 1 o'clock in the morning as we were leaving, and they were still doing autographs outside their bus, and there was a line of 300 people," he said.June 1, 2015: 97X Green Room, St. PetersburgTwo weeks after releasing their latest album Blurryface, the duo dropped by 97X for a promotional Green Room acoustic show. Dun played a station intern, "DJ Spooky Jim," assigned to interview Joseph, who played stripped-down ukulele versions of Tear In My Heart, Lane Boy and Holding On To You. "It was the first time we had dozens of people lined up outside, screaming kids, trying to misdirect them to get (the band) in and out of the building without getting accosted," Weiss said. "It was around that point that we realized, this is not just an alternative thing anymore."Dec. 5, 2015: 97X Next Big Thing, TampaTwenty One Pilots' local journey came full circle at the biggest Next Big Thing 97X ever, a sellout of the MidFlorida Credit Union Amphitheatre. "It was so cool to watch them go from being literally the opening band three years prior to headlining our sold-out show," McBroom said. It seemed like half the crowd was wearing the band's trademark red and black, with some in makeup and costumes. "You could tell that it meant something to them," Connelly said. "They didn't do many radio shows (that year), and they probably will never do radio shows again — they've gotten too big. But they specifically picked those markets they wanted to take care of, and luckily, we were one of those stations."Feb. 28, 2017: Amalie ArenaFive years after their first performance in Tampa, Twenty One Pilots are returning for their biggest gig yet, one that sold out months ago. A while back, I was talking about this show with Kevin Preast, Amalie's senior vice president of event management, and I mentioned what a strong market Tampa has been for them over the years. He laughed. "Right now, every market's a good market for Twenty One Pilots," he said. As Joseph put it during his Grammy acceptance speech: "Anyone from anywhere can do anything." Their rise in Tampa Bay is proof.Contact Jay Cridlin at [email protected] or (727) 893-8336. Follow @JayCridlin.