Boston band Bent Knee have a sound that you could never pinpoint. It doesn’t have any geographic landmarks like the Chicago Blues or the Seattle Grunge scene. It exists on its own plane, unlike anything else. They play with a crazy intensity that quickly infects the crowd into a kind of savage wildness normally attributed to moshing heavy metal fans.

They’re not quite playing heavy metal, though. It’s hard to describe exactly what it is, but if I had to try I’d say it’s prog rock with echoes of King Crimson and Rush. Guitarist Ben Levin doesn’t shred quite as hard as Robert Fripp, though he probably could if he so desired. The vocal work of Courtney Swain is really the key to the whole thing-a modern Grace Slick who can erupt into a wail as good as any you’ve ever heard.

There’s also a soft side to the band, demonstrated by the violin work of Chris Baum. They show a real sensibility for pop music as well, which likens them more to bands like Arcade Fire and The National. It’s in these more vulnerable moments that the band tests their connection with the audience; when the energy in the room is a collective frenzy, it’s easy to feed off of. It’s very different when things are quiet, and the conversation between the band and the fans is as much about what is unspoken. In this, Bent Knee truly finds their power.

Their regular drummer broke his leg, so Gatherers drummer Adam Cichocki pulled double duty playing with both bands. He did a great job and there wasn’t much of a difference in the quality between this and the first time I caught Bent Knee last year when Gavin Wallace-Ailsworth was with them. He should be healed up for the just-announced show their playing December 1 at Bottom Lounge with Haken and Leprous.