The difference between noise and noisy rock is in the ear of the beholder, something Pterodactyl realized after initially aping a drunken, cacophonous wreck. Adding structure to their throttling throb, they couch little gems of guitar creativity in jagged squalls of feedback, and stray scraps of melody beneath the cushions of their sofa-set skronk. Bassist Kurt Beals plays with a Big Muff pedal, ensuring choppy rapids of distortion for guitarist Joe Kremer to surf, slicing in and out of Beals' droning rhythmic waves with spiky, jiggling leads. They bounce back and forth between discordant, squiggly clatter,and hypnotic buzz, while drummer Matt Marlin holds down the rollercoaster pace. Indeed, the Brooklyn trio has several gears, ranging from the hardcore rumble of their incendiary "CHX BX" to the ringing post-punk melodicism of "Safe Like a Train," which sounds like an agitated Jawbox, or the nascent Pere Ubu-isms of "Rampage 1." Like abstract expressionism, it's hard to separate the merely mediocre from the crap in noise rock, but there's no mistaking an act like Pterodactyl, which gives such supple shape to raucous racket. Their debut, Blue Jay, is perversely entertaining for all its squawking pandemonium, and they bring the same intensity to their live performances.