Rachel Jayson, Scott Dakota and Lainey Schulbaum cut loose after performing as the Trio Microcosmique at Outpost 186 in Inman Square, Cambridge, on May 27, 2009. (Photo courtesy: Scott Dakota)

Rachel Jayson, Scott Dakota and Lainey Schulbaum cut loose after performing as the Trio Microcosmique at Outpost 186 in Inman Square, Cambridge, on May 27, 2009. (Photo courtesy: Scott Dakota)

Outpost 186 hosted a three-part microtonal-music night Wednesday, playing up the touring Thomas Helton on upright bass but including locals the Trio Microcosmique and bass clarinetist Todd Brunel. (The trio was formed a week ago just for this gig and comprises Scott Dakota, Lainey Schulbaum and Rachel Jayson.)

“Microtonal” brings to mind what to Western ears might seem like a lot of droning, and, to be sure, what went on wasn’t for everyone — but it wasn’t merely tedium and allowed for as much range as you might find at a night with a full orchestra. That is, if you don’t like the current microtones, just wait a microminute.

Helton did two pieces in his hour or so alone, and in each he produced sounds totally unexpected from the bass, although maybe not from this particular bass, which looked well-used — a Texas bass, at home on the frontier. At times Helton made shrieks like metal on metal by sawing his bow on the strings below the bridge while strumming two strings above; maintaining the strumming, he dragged the bow up the unused center strings to create a crazed skittering; still maintaining the strumming, he whipped the bow in the air off to one side for a chilling flapping of wings. At another time, plucking the bow violently around the C bout or lower bout produced surprisingly scary, and riveting, noises. The only unexpected use of the bass that was also unsuccessful was when he used his hand to rub it front and back, which sounded only like someone using his hand to rub a bass’ front and back.

His improvisational work with Brunel was also a mix, emerging into the sublime by lurches out of the clumsy. In this case, the key stretch was when Helton settled into a laid-back, slightly menacing but cool thrumming as background to an aural attack by Brunel. The image: Robert Mitchum sauntering down a black-and-white street in broad daylight, appearing totally at ease despite the screeching psychosis inside waiting to burst. Another improvisation, in which the pair swapped the lead several times, continued the argument between mournfulness and violence.

The Trio Microcosmique played on a different palette, ranging from soaring to pulsing, but always with key and harmony in mind, frequently looking at each other in silent communication, and Dakota even gave some encouraging explanations of what the players were about to do.

Schulbaum, showcasing her classically trained side instead of the broad(!) comedy of her Steamy Bohemians gig, assured from the beginning that the trio would be a gentle and pleasant ride.

“Don’t be scared by the ‘microtonal’ tag!” she told her Facebook invitees. “The arid, astringent art thing is cool — don’t get me wrong — but we’re not about that. No frets or fixed pitches are present here, so from all possible notes we can choose to play the extra pretty and harmonically unified and interesting ones. Notes you don’t ordinarily hear, new sounds! It’s natural intonation, like a string quartet or a cappella vocal group. And for the math and history buffs among you, just Intonation utilizes whole number frequency ratios in the style beloved of the ancient Sumerians, Egyptians, Vedics, and that Pythagoras dude, with some modern twists.”

“Artsy this may be,” she said, but fun as well.

Despite her assurances, In fact betrayed by her assurances, the music can’t help but be a bit cerebral. But the performers made sure that wasn’t a bad thing, and made it adventurous, as well.