We promise not to say that this double A-sided single sticks to your ribs — oops, too late — because the place it really hits is that floating, synapse-trigger space where the head meets the hips. That’s what Boston’s RIBS were after, and got, with last year’s audaciously kinetic “British Brains’’ EP, which announced the arrival of a bold new musical voice whose promise extended well beyond local borders. For “Locrian Singles,’’ available now as a free download from their site, the foursome’s kept the element of surprise intact but taken a darker detour. This time out, we get gloomy yet doomily delicious dance-rock backlit by singer-guitarist Keith Freund’s expressively mercurial falsetto, plus what sounds like a new predilection for foggy synthesizers. Except that there aren’t any. Believe it or not, it’s actually layers of bass, guitars, and vocals ingeniously run through an array of distortion and delay effects that give the Cure-ish “Cosmos’’ its sense of otherworldly atmosphere and epic drift. It’s a welcome chill-out after the glammy, electro-industrial clang of “Please Don’t Go,’’ a Nine Inch Nails-meets-Muse salvo whose steely sheets of sound hammer the message home loud and clear: RIBS aren’t leaving anytime soon.
“Locrian Singles’’ can be downloaded at hear.ribstheband.com.