Mastodon's Brent Hinds, second from left, might have a similar-looking forehead to Opeth's Mikael Akerfeldt after last night.

Mastodon's Brent Hinds, second from left, might have a similar-looking forehead to Opeth's Mikael Akerfeldt after last night.

The opening band, Ghost, had finished its set a half-hour earlier, and fans were starting to push back toward the front of the stage. Instead of Opeth's members walking out, though, a tour manager stepped up to the microphone. “Quite a serious accident,” were the words that reverberated through the crowd.

Mikael Akerfeldt

Mikael Akerfeldt

Opeth was forced to cancel last night's concert with Mastodon at Myth nightclub in Maplewood after frontman Mikael Åkerfeldt was rushed to the hospital with a head injury. According to the band's management, the 38-year-old singer/guitarist with the beloved Swedish death-metal quintet cut his head open while walking off the tour bus. He was rushed to the hospital and reportedly had to get five stitches. It is not yet clear if he will have to cancel more dates. Last night's show will be the only cancellation from the injury, the band's reps are now saying.

***Update: Here's part of a statement posted on the band's Facebook page:

He's doing OK now and we expect him to be up and running (though slightly slower) again for tomorrow's show and onwards. ... Mike & the band were very disappointed not being able to play yesterday but thank everyone for their understanding and for the tons of get-well-wishes Mike has received since.

The incident apparently happened just before showtime. Fans reported seeing Åkerfeldt walk into the venue around the time doors opened. Mastodon drummer Brann Dailor made a statement at the end of his band’s set that made it sound like it was quite a dire injury. “We hope our brother Mikael is OK,” Dailor said. “That’s all I could think about throughout this entire show was how my friend is doing.”

Refunds were not officially offered, but the cancellation amounted to another rough break for the folks at promotions company AEG Live. This was another concert they had to move to Myth from the Brick, after fans were given refunds for the Brick’s overcrowded opening concert with Jane’s Addiction.

Mastodon certainly did its best to give fans all the bang for their buck. The Atlanta prog-thrashers stretched out their set to two hours -- which, based on their intensity level and nonstop approach, is physically equal to about a four-hour performance by your average rock band. As usual, they played without spotlight but had a cool, black-light-tinted array of darker stage lights. Also, they said not a peep to the crowd between songs (aside from Dailor’s comments at the end). Such shy Southern gentlemen.

Highlights included the explosive opener “Black Tongue” and the moodier, sludgier “Thickening” near the start of the set. Midway through, the band segued straight from the guttural gem “All the Heavy Lifting” into an ultra-rapid and fierce “Spectrelight.” The best of the best came toward the end with the thrashy epic “Blood and Thunder,” played with full-throat fervor. The set closer, “Creature Lives,” was a surprise that seemed to be tacked on in tribute to Åkerfeldt. Here’s the entire set list (there was no encore):

Black Tongue /  Hand of Stone  /  Crystal Skull  /  Dry Bone Valley  /  Thickening  /  Octopus Has No Friends / Blasteroid  /  Stargasm  /  The Hunter  /  Crack the Skye  /  All the Heavy Lifting  /  Spectrelight  /  Curl of the Burl  /  Bedazzled Fingernails  /  Aqua Dementia  /  Ol'e Nessie  /  Blood and Thunder  /  The Sparrow  /  Creature Lives