Microtonic Harmonic plays bluegrass with an unmistakable enthusiasm.

On a Wednesday night in an apartment above Holman Jewelers in Pacific Grove, newly renamed bluegrass band Microtonic Harmonic spends more than an hour perfecting a few closing notes of Django Reinhardt’s “Minor Swing.”

The seriousness with which they fine-tune tiny segments of their songs has helped them earn a burgeoning local audience– and the opportunity to open for long-time nationally touring bluegrass act The Hackensaw Boys at Monterey Live this Saturday.

The high-ceilinged, Victorian apartment is sparse, except for the four musicians, a Ry Cooder record and a couple half-full bottles of red wine.

Microtonic Harmonic, formerly known as Dave and Evan, was born less than a year ago with a mostly clear identity in mind. (The band, usually a duo made up of Evan Francis on guitar and Dave Holodiloff on mandolin, will have two additional members sit in with them for their upcoming show at Live: John Klein will play upright bass and Laurie Kost will play fiddle.)

“We’re definitely a bluegrass band, but we dabble in reggae, folk-Celtic and gypsy jazz,” Holodiloff says.

Pacific Grove’s 22-year-old Holodiloff has quickly become a fixture on the local music scene, playing guitar with his rock/funk/jam band trio Sheepdog on the Set, who regularly perform at Monterey Live. Always dressed in a smile, he wears long blond hair tucked behind his ears.

He grew up around music. Both his parents are semi-professional singers who exposed him to classical music and opera at an early age. He started playing the drums when he was 10.

If Holodiloff’s guitar and mandolin aren’t handy, he gets his musical kicks through “beat-boxing or drumming on random things.”

He has always had a strong admiration for mandolin players like David Grisman and Sam Bush. So he taught himself how to play about a year ago after purchasing a mandolin for $20. It was around this time that he first met his perfect bluegrass counterpart, Francis.

“We jammed at this party,” Holodiloff says. “Evan knew how to play “Throwing Stones,” an obscure song by the Grateful Dead, all the way through.”

The rest is history. Francis and Holodiloff have been playing everywhere, from the Monterey Farmers Market to the Big Sur River Inn.

The duo typically plays traditional bluegrass covers that range from “Whisky for Breakfast” to “Blackberry Blossom.”

“We do have a few original songs,” Holodiloff says. In fact, Microtonic Harmonic will be debuting a new song at their Saturday show.

Francis, a 30-year-old assistant technician and life support engineer at the Monterey Bay Aquarium, has an affinity for bluegrass that rivals Holodiloff’s.

The Oakly, Calif., native says he’s been playing music for 15 years, beginning with a heavy metal and hardcore phase, then gradually progressing to folk and bluegrass.

Francis agrees that he and Holodiloff make a good match. They point out that they enjoy the same music; more importantly, Francis adds, they move each other to further explore their already rather serious passion for bluegrass. “Every time I play with [Dave] I get inspired,” he says.

These aren’t idle words. After a recent appearance at the Solar Tour and Sustainability Fair, the two stuck around long after their collaborators for the day had left, playing with full-fledged intensity just inches from one another, continuing even as organizers packed up display stands and a bike-operated blender.

Microtonic Harmonic opens for The Hackensaw Boys 9:30pm Saturday, Nov. 1, at Monterey Live, 414 Alvarado St., Monterey. $10. 375-5483.