More so than Son of the Tiger, Sleep Forever witnesses the Big Sleep struggling to reconcile their prog-rock and dream-pop leanings. What happens, then, when the forceful and frenetic clashes with the lush and lurching? The Brooklyn trio of Danny Barria, Sonya Balchandani, and Gabe Rhodes doesn’t actually negotiate an answer on its sophomore effort. Sleep Forever is less about adaptation than demarcation. Its 12 tracks oscillate between guitar-charged frenzy-mongering and aching drifters. Little stands in between. You gradually realize that the Big Sleep are insistently disinclined to tinker with and possibly spoil the purity of their disparate tastes. So they wall them off from one another. The outcome is a skillful but overly careening and unfocused album, pocketed with niche sounds.

The prog-rock genre typically calls to mind dense, extended compositions that wax and wane with disorienting effect. Sleep Forever rebuffs that expectation. When not in shoegaze mode, it mainly serves up three-and-a-half minute cuts, often instrumentals, that shirk progression and dive impatiently into eruptive guitar freakouts. They are grounded one moment and then in full, frenetic flight the next, with obvious neglect of the journey upwards. The brittle thump that introduces “Slow Race” quickly flares into a screeching tirade of reverb and distortion, leaving scant breathing room in the middle. “The Big Guns” is equally grating and only marginally more interested in progression. As instrumentals, neither communicates much beyond unwieldy aggression.

Even when Danny Barria and Sonya Balchandani enter the fray vocally, the blunt sonics of Sleep Forever often drown out their contributions. On the racing “Bad Blood”, which might as well be an instrumental, Balchandani’s droning moan bleeds into the sprint of hazy guitars. The co-vocalists up their tenacity on “Tigers in Our Hearts” but still lose out to the song’s repetitively thrashing jams. With all this energy, the Big Sleep may be going for urgency but the end result is more an overload of exhaust.

In bold contrast are the more temperate tracks that leave resonant impressions without creating so much rubble. On these, the Big Sleep resist their fiercer instincts and trade in a somberly rainy aesthetic. Together, the final three cuts on Sleep Forever almost function as a mini-suite, ruminating uneasily on the confusion and despair of solitude. The leadoff, “Organs”, rides a woozy march of synth keys that evokes a listless mood but is still too musical to permit tedium. The second entry, “So Long,” is a perfectly paced funereal dirge. Its rich pianos gently rise and fall for three swooning minutes without attempting a firm climax. Triumphant and elegiac, it’s like a martyr’s walk toward doom. What’s more, both are instrumentals. Only the finale, “Sleep Forever”, utilizes vocals (in this instance, from Barria), which lend literal expression to the album’s trials with urban isolation: “There’s no place left for us to go / We drive for miles and miles and miles”.

In between the poles of noisy post-rock and dream-pop, the Big Sleep do locate momentary points of accommodation that reveal the upside to departures from form. The tickly Spanish acoustics at the outset of “Little Sister” are a cleverly effective setup for the simple melody and rhythm of the main passage. Even the lead single “Pinkies”, with its punchy wash of guitars, doesn’t devolve into a bustle. It’s compact but complete. Only a handful of songs on Sleep Forever share this feel.

Even though the Big Sleep seem most natural in a fevered fit and can be vividly affecting while restrained, they won’t reach their peak until the two modes are properly bridged. They can maintain their guitar heroics but should pare down the white noise. They can still decorate their pathos with weeping pianos and synths, even while injecting it with more vitality. The Big Sleep can do all of this and forge the full-bodied, full-blooded compositions that have been eluding them.

• "Bad Blood" player
• "Pinkies" player