The Pinhook, Friday, Aug. 8, 9 p.m., $10 FLESH WOUNDS
Cat’s Cradle Back Room, Friday, Aug. 8, 9:30 p.m., $8.

On Friday, Spider Bags and Flesh Woundsthe two most exciting garage-rock bands in the Trianglewill both celebrate the release of their new albums in a small local club. For Spider Bags, it’s Frozen Letter, their fourth proper LP and first for Merge. For Flesh Wounds, it’s the self-titled follow-up to this year’s Merge-stamped “Bitter Boy” single, issued by the trio’s new Snot Releases. These two bands share a genre and have shared a label, but they won’t share a stage this weekend. Spider Bags will be at Durham’s The Pinhook, while Flesh Wounds headline the Cat’s Cradle Back Room in Carrboro.

The separation is more telling than an instance of unfortunate scheduling: These days, Spider Bags and Flesh Wounds operate on such opposite ends of the garage-rock spectrum that the validity of the catchall term seems suspect at best. Both albums are excellent, but in different ways and with distinct goals. One does not recommend the other.

Spider Bags have long adhered only to a loose definition of garage rock, eager to shift gears between psychedelic rave-ups and self-deprecating sulks, between Memphis rock ‘n’ soul and sputtering punk. On 2012’s Shake My Head, the band finally managed to do all those things at once.

Frozen Letter‘s first four songs mostly pick up where Shake left off: First single “Back With You Again in the World” builds momentum from the lockstep rhythm section of drummer Rock Forbes and bassist Steve Oliva, while frontman Dan McGee bends strings toward scrappy twang. “You know I’ll always be honest in everything that I do,” he promises. In two-and-a-half minutes, the song sums up the Spider Bags repertoire to date; a steady, propulsive rhythm lays the groundwork for McGee’s rambling guitar and sardonic confessions of loutish behavior and the consequences or redemption that follow. Even as McGee shifts into more imagistic writing for “Japanese Vacation” and “Chem Trails,” the band maintains its streamlined thrust.

And “Summer of ’79″a slight revision of the original, by Golden Boys frontman John Wesley Colemanoffers a Spider Bags throwback. The performance challenges baselessly nostalgic rock ‘n’ rollers with a simple backbeat and guitars that swivel from roaring power chords to sidewinding leads, from Chuck Berry to Crazy Horse. “Why you wanna be a Rolling Stone?” McGee bellows. “Why you think your daddy is the king of rock ‘n’ roll? You weren’t before ’79, you weren’t there, you weren’t alive.”

As soon as the declaration is made and the record spins into its second half, Spider Bags dive into new territories. “Coffin Car” is a wandering six-and-a-half minute narrative that finds McGee singing about frozen letters and shining smoke stacks over a winding guitar and deliberate bassline. The acoustic ramble that begins “Walking Bubble” picks up psychedelic embellishments and gospel inflections, a boulder rolling over a series of curious mountain towns. By the time “Eyes of Death” finds its Sonics-meets-Howlin Rain gusto, Frozen Letter has ventured well beyond the garage. They sound crazed.

Where McGee rarely hollers or yelps anymore, Flesh Wounds’ Montgomery Morris keeps his voice at full throttle. Where McGee increasingly writes abstract lyrics with malleable meanings, Morris is happy to yell plainly about the scourge of Chapel Hill drivers. Where Frozen Letter stretches eight songs over 33 minutes, Flesh Wounds’ self-titled effort crams 14 into 32.

Loud, brash, direct and succinct, Flesh Wounds are quintessentially a garage band. Any misunderstandings stem from low fidelity and strained vocals, not ambiguity of intent. Drummer Laura King drives the band with a heavy hand and guitarists Morris and Dan Kinney revel in their distortion. They fill these songs with an in-the-red adrenaline rush that will feel familiar to fans of garage-punk heroes like The Oblivians or Teengenerate.

But this isn’t just petulant primitivism. Surprising influences emerge frequently from their mastery of the budget-rock template. “Get Off the Lawn,” for instance, is a proto-hardcore ripper with a ’70s blues-rock guitar solo. It also serves two hooks back to back. Elsewhere, the band draws not only from the Nuggets and Killed By Death sets but from blues murder ballads (“I’m Gonna Dig Myself a Hole”), surf rock (the double-picked guitar solo of “Bushy Boomerang”) and British Invasion pop (“I Can See”).

Still, Flesh Wounds aren’t trying to transcend their loud-fast foundations. They’re inviting influences inside where Spider Bags are turning some of the same influences against themselves. The two might share a common ancestor, but on these records, they feel like distant, friendly cousins.