Just when my mailbox makes me feel like modular synth jammers have taken over the world (not an altogether unpleasant feeling, but still), there’s always a great band lurking around the corner to remind me of the creative bliss in songform, melody, and collaboration. Today, that band is Grex, a playful and adept group from Oakland who just released their debut as a trio, “Monster Music,” on their own Brux label.

Grex has been around for several years as a duo with Karl Evangelista on guitar and Rei Scampavia on keys/horns, frequently collaborating with guest musicians. Their earlier recordings, which can be found on their Bandcamp page along with “Monster Music,” feel more like compositional workshop outings, methodically combining improv chops and songwriting prowess into surprising left-field arrangements that carry a bit of “new music” formality. But with the addition of percussionist/drummer Robert Lopez as an official member of Grex, the beautifully-crafted melodies of older pieces like “Up Popped the Snake” from the band’s repertoire are feeling more like familiar pages in a well-worn songbook. “Monster Music” packs as much aural nutrition as earlier iterations of the band, but this lineup also knows how to swing and how to rock outrageously.

Opening track, the instrumental “Toy Time,” is a great introduction to the Grex approach. With nimble percussion expanding on 60s surf beats, and unpredictable, serpentine unison lines between guitar and organ, you can’t help but smile as the music veers in and out of free improv passages. And I just adore the guitar tones Evangelista uses for melodic line part-playing: with a touch of overdrive and a hint of rotary speaker swirl, his sound blends gorgeously into organ tones, a signature orchestration that returns in unison lines all over the album. When he rolls back the Leslie swoosh, he picks up a perfect gritty edge, sliding between Charlie Hunter and Henry Cow-era Fred Frith vibes with ease.

This is one of those unusual albums that can serve capably as a bridge between song-oriented and really “out”-improv-oriented listening. Over half of the tunes feature prominent vocals, Scampavia taking most of the leads, and it’s obvious that these songs were built to emphasize accessible, memorable melodies, no matter how far they might stray in the course of their arrangements. The instrumental pieces always have hummable, or at least quite danceable, hooks. And the cover tunes–“Guinea,” a late-70s Don Cherry number, and “Holy Family,” an old Ayler head included as an unlisted bonus track–have melodies deeply rooted in blues and gospel music, particularly tuneful choices from their composers’ respective catalogs. But those solo sections. . .

With the exception of the straight-ahead ballad “Love Song,” all of these arrangements leave room for solo/free improv work, and the group approaches most of these passages with a near-opposite sensibility, eschewing melody for density, embracing tone clusters, tons of effects, and simultaneous freakout sessions. It can be a little jarring at first, as the melodic sections of Grex tunes are played with a lot of sensitivity to dynamics, focused on nuance and detail instead of loud, broad strokes. Every group needs some kind of strategy to succeed with contrasts this extreme, and in the case of Grex, I think it’s their sound choices that make it work. The organ tones have a vintage 60s timbre, reminding me a lot of Don Preston’s dancing-on-the-keys approach in the chaotic sections of early Mothers jams. If those same parts were played on piano or using some harsh synth tones, I think things would feel more academic/serious or maybe confrontational, but the organ keeps things playful and approachable no matter now close the actual notes get to Cowellian clusters. Ditto for the guitar tones: Evangelista lays on plenty of effects when the moment is right, but his basic tone avoids those hyperfuzz sounds that cut you in half. While that works on some recordings, these sounds combine to allow for very listenable sections of group improvisation where the fun of interaction is clear to listeners without compelling folks to duck for aural cover.

There are several great guitar solos on “Monster Music” that stay closer to conventional jazz vocabulary and even blues work: the cover of “Guinea” mentioned before draws out more of a deep blues feel than the original, and “Christmas Song” works lots of tasty volume swells and country-ish bends into a playful, mostly legato solo section with a nice hint of delay. But my favorite moments on the album tend to be the written instrumental passages: the amazing lines introducing “Toy Time” and “Mole Cricket,”or the complex rhythmic shifts, chromatic mazes, and whammy pedal workouts throughout the brilliant “Hurdles.” But my choice for a single from “Monster Music” would have to be “Romancing Stone,” rich with introductory unison lines folding in on themselves, great vocals from Evangelista that are warmly reminiscent of Mike Keneally, awesome harmony vocals in the chorus, and lots of room for thoughtful drum work to shine in the open section at its center. And be sure to dig into “Up Popped the Snake,” too–as mentioned earlier, the basic tune has appeared on a couple of previous Grex recordings, but this new trio arrangement hangs onto the haunting melody of the original while drawing listeners a little closer than previous versions with great organ/guitar interplay and great contrasts in drum parts across sections.

Grab your medium of choice (LP, CD, digital) at the Grex Bandcamp.