In the world of heavy music, few bands embrace dynamics and negative space like Kowloon Walled City. Since forming 15 years ago, the band has increasingly refined its deconstructed approach to noise rock, math rock, and doom. Now, with Piecework (Neurot Recordings/Gilead Media), the band’s fourth album and first in six years, Kowloon Walled City reaches new levels of restraint. Songs are bleak and slow, but also shorter and more concise. (Seven songs clock in at about 30 minutes.) There are stretches of near silence. While the band has always operated under the MO that less is more, it has doubled down on that ethos for Piecework. Singer/guitarist Scott Evans and guitarist Jon Howell, the main songwriters, self-imposed restrictions to push themselves creatively—“restraining ourselves into oblivion,” as Howell put it. Songs are written in more straightforward time signatures. Evans and Howell also changed their guitar rigs to sound more “clean and clanky.” With the gristle stripped away, bone and muscle remain: drums decaying in a room, bass strings rattling, a lonely guitar chord. Sometimes, it’s almost uncomfortably barren. But the negative space also amplifies the ruptures of heady aggressiveness that anchor Piecework. Angular guitar notes from Howell skew off the neck, dissolving into space. Ian Miller’s bass lines churn in the muck. Drums and cymbal smashing by Dan Sneddon punctuate dead air.(Sneddon, formerly of Early Graves, makes his recording debut with the band five years after joining.) There’s sadness and anger in Evans’ shouted vocals, but also a desire for something better. Through the resignation and regret, Piecework also hints at perseverance and hope.