Throughout the day of the concert, it seemed as if there was a chance that the sold-out Alabama Shakes show at Thompson’s Point in Portland wasn’t going to happen at all. Weather reports offered a forecast for severe thunderstorms that remained unwavering all week, and as Saturday evening approached, the State Theatre crew cooked up contingency plans as fans feared the worst.

The phrase “lobster roll festival,” referring to the infamous Thompson’s Point festival (not hosted by the State) that ended in chaos, was even whispered in fear as a potential outcome. Ultimately, however, organizers bumped up the set time, and the move turned out to be savvy – the sky didn’t open up until the encore.

It was a fortuitous turn of events for the venue, which seems to have unusually lousy luck with weather, and also for the fans. Alabama Shakes has enjoyed a rapid rise to fame in the last five years, ascending alongside a renewed interest in American roots music while also transcending the trend, and they currently stand as one of the biggest rock bands of the millennial generation.

Many people came to catch a glimpse of frontwoman Brittany Howard, a born rock star who is inching near icon status before her 30th birthday. She didn’t disappoint them, as she exuded style and personality to fill a concert space twice as big, and delivered a riveting performance that showed off both her singing and her guitar chops.

Her songs typically fall into two types – there are ramshackle blues-rock songs, as well as quieter compositions with whispers of gospel. The subtlety of the latter songs didn’t always travel well at Thompson’s Point, a venue that transforms from a concert vibe to community picnic as you get farther from the stage, but the boisterous nature of the former served up many of the set’s highlights. The rest of the band produced a soulful clamor that suits her performance nicely. They don’t quite pin down the on-point swing and carefree funk of the classic Muscle Shoals sound of the 1960s and 1970s, but they make up for it with an enthusiastic rattle, as if their goal is to sound like they’re shaking up rocks in a can.

It all adds up to a sound that feels traditional and contemporary at the same time. Perhaps their most well-known song, “Don’t Wanna Fight,” has little of the hallmarks of a massive hit – it isn’t terribly catchy, it doesn’t feel modern and it is built upon just one riff that closely mimics the single line of the chorus. But when the music drops out near the beginning, and Howard emits a wordless cry that emerges somewhere between a gasp and a howl, it almost seems to give birth to something new and thrilling. When they played the song in concert, it resounded throughout the tiny peninsula, forming a powerful punch alongside the equally strong “Gimme All Your Love.”

Those are the kinds of moments that drew people to the venue for its only sold-out show of the season, serving as the reward for those who remained committed to the end. When the band reached the climax of “Miss You,” fireworks even went off behind them at the Sea Dogs game at Hadlock Field. It was one of those nights where everything just fell into place.

Robert Ker is a freelance writer who lives in Portland.