Imagine this scene: The biggest rock star in the world is about to give a free concert in Central Park, but he doesn’t know that a corrupt politician has hijacked the event to make it look like an endorsement. So an alien comes to earth to save the day, but has to take human form to communicate. The alien crashes the stage at the big show and chaos ensues.

If that sounds like the setup for an outlandish rock opera, you’re exactly right, The opera, “Beasties” was written by musician and jack of all trades Gary Sohmers, who’s been around local and national scenes since the ’70s. He’s assembled an all-star local cast to perform it, and the interplanetary showdown will happen at the Regent in Arlington on Oct. 10 and 11.

“Beasties” was partly inspired by his politics – suffice to say he’s not a conservative – and partly by his love of vintage sci-fi. “I’ll say I was triggered by the events of January sixth, which made me think of an alien coming down to save the planet.” The cast includes Liz Proteau, who records under the name Endelle, and Mach Bell, who led the vintage Boston band Thundertrain and later fronted the Joe Perry Project. And the role of the hero is played by Barrence Whitfield – the local rock/R&B voice who in a perfect world would already be one of the biggest rock stars on earth.

He was one of the first singers that Sohmers approached. “I thought he was crazy,” Whitfield said.  “But honestly, I also thought it was a really interesting thing that nobody else is doing at the moment. What Gary’s putting together has different kinds of music and a lot of audio-visual going on, so I think you’ll be seeing something really interesting. I’ve been doing everything else lately, from (jazz visionary) Sun Ra to country music, so here’s one more notch on my resume, if you will.”

Originally from Chicago, Sohmers already had a mile-long resume before he came to Boston. He began producing concerts in Chicago where he took young groups called Styx and Sick Man of Europe under his wing (the latter got bigger after changing their name to Cheap Trick). His first band Windjammer included drummer Butch Vig, who went onto produce Nirvana’s “Nevermind.” In Boston he spent nine years as the production manager for the Metro on Lansdowne Street, and now deals in collectibles: He runs New England Comic Con and for 13 years was an appraiser on PBS’ “Antiques Roadshow.” For that he says, “I deal in the three D’s – Death, divorce and downsizing.”

He’s already recorded a studio version of “Beasties” which can be streamed online (the recording featured legendary UK singer Chris Farlowe, for whom the Rolling Stones wrote “Out of Time”). And his current goal is to bring “Beasties” to a wider audience.

“Reality says that an artist can’t make a record and become popular in the commercial sense (anymore). But there are so many great shows that have gone to Broadway like ‘American Idiot,’ ‘Jagged Little Pill’ and ‘Hadestown.’ Then there are things like ‘Tommy’ and ‘Hair’  that have lasted 50 years because the music and lyrics are so compelling. The goal here is to come up with good music, good storytelling and ideally a message. And the message is kindness.”

Mach Bell and Gary Sohmers, left to right, in rehearsal. (Photo John Koumoutseas)