Dissatisfaction is strewn throughout the new albums by England’s Dirty Pretty Things and California’s Earlimart, both out today. How the two rock bands choose to express that restlessness — and why they’re so riled — is radically different, and boils down to what makes one a promising failure and the other a disarmingly curious gem.

“Romance at Short Notice,” the sophomore release from Dirty Pretty Things, suffers when compared with the output of singer-songwriter Carl Barât’s previous outfit, the Libertines. It’s an unfair, if inevitable, yardstick: The Libertines, the impudent garage-punk quartet Mr. Barât formed in 2001 with Pete Doherty, were an ideally decadent blast of British rock ‘n’ roll, slapped with a latter-day Clash label. The band’s 2002 debut, “Up the Bracket,” and its 2004 self-titled follow-up tethered unruly appetites to pulse-quickening guitars, drums, and bass. The band’s various drug addictions and tabloid-ready lifestyles only magnified its reputation for living the image it churned out.

Lightning hasn’t struck twice for either Mr. Doherty (who was evicted from the Libertines and now fronts his own band, Babyshambles) or for Mr. Barât’s Dirty Pretty Things, whose 2006 debut, “Waterloo to Anywhere,” was a consistently even-keeled garage-rock album but lacked the combustible sparks that made the Libertines so attractively unstable.

“Romance at Short Notice” does and doesn’t correct that deficiency. Thematically, the album’s 12 songs offer a more consistent batch of material, backed by a more confident sounding collection of tunes. But the album is fraught with bitter nostalgia and reactionary cynicism, with Mr. Barât sounding more like a man wrestling with midlife than a musician who just turned 30.

Lead single “Tired of England” captures that inconsistent mood. The song opens with a stately brass processional that is cut short by a rush of trebly guitars, purposely recalling the melody to the Smiths’ “Panic.” Like that romantic ode to home, “Tired of England” both celebrates and decries Mr. Barât’s home country, tempering rosy affection for the scents of London on a warm day with a screed on the disrepair of some its neighborhoods (“The state of the roofs is a pity, though,” he laments).

But the song never generates a coherent temperament, even one as standard as a love-hate relationship. Mr. Barât sounds sincerely fond of London — warts and all — in one moment, then resorts to pithy passive-aggression — “don’t drink yourself to a lonely death / in casinos on crystal meth” — during the bridge.

It’s as if Mr. Barât loves the city but holds himself above its inhabitants, a disposition reinforced in the album’s lead track, “Buzzards and Crows,” in which he sneers at the fashionable emptiness of so-called coolness. “I need to be recognized because I need to be self-assured,” he sings, and it’s difficult to tell if he’s mocking his own past or the generation of hipsters the Libertines inspired.

Even in ballads such as “Come Closer” and “Faultlines,” Mr. Barât sounds as though he’s trying to find his bearings in a world he no longer understands. “Yeah, I get the fear that I cannot be bothered,” he blearily offers in “Faultlines,” a verse that ends with a fleeting impulse: “You know you want to run away.”

Backing all this ennui is Mr. Barât’s familiarly elemental rock, informed by equal parts of the Clash and 1990s Brit-pop. It’s perfectly hummable, but it never accents or even complements the tension in his lyrics. In fact, “Romance at Short Notice” works best when Mr. Barât balances his songs’ moods with more disposable sentiments. “Plastic Hearts” is a skipping piece of near bubblegum pop whose biggest concern is asking an unnamed woman to “melt my plastic heart and help me move on.” Just a hint of backing strings adds a nice touch of loneliness to the ballad “The North.” And “Chinese Dogs” hitches its liveliness to a runaway guitar line that lends the song a sense of swirling chaos, allowing Mr. Barât to alight upon the infectious energy he dished out in his previous band.

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The Los Angeles-based Earlimart takes an entirely different approach to exploring its unease with “Hymn and Her,” its sixth album. Now a duo made up of singer-guitarist Aaron Espinoza and keyboardist-vocalist Ariana Murray, Earlimart creates airy, soaring songs that feel as light and fleeting as a dream. Inside this floating bubble, though, the duo sings about displacement, disappointment, and trying to escape an increasingly threatening reality. Sunny songs rarely explore such unambiguously uncertain terrain.

“Cigarettes and Kerosene” is a prime example of the band reaping such dramatic tensions from of its low-key music. Musically, the song weaves a simple mid-tempo drumbeat with gradually added sounds that flesh out the melody; a soft buzz enters in the second verse, hiding in the back of the mix like thunder in the distance, and a patch of nervous strings finds its way in toward the very end. Throughout the song, Mr. Espinoza utters the faintest hints of a disturbing tale practically under his breath, barely clarifying the song’s title — “cigarettes and kerosene / you light the match and fall asleep / you’ve found freedom.”

The album’s centerpiece is “Before It Gets Better,” a deft piece of pop. Ms. Murray sings the lead, and, backed by the song’s soft, piano-driven melody and light percussion, she recalls Aimee Mann at her most coffeehouse-crooner. The song itself begins as just that sort of woozy pop, as Ms. Murray coos, “There’s a light that just won’t go out / no matter what they do.” It’s an ambiguous line that could easily set up a tale of human tenacity, but what follows is a dystopian, paranoid rumination of impending doom, with Ms. Murray singing, “It’s a deathtrap, it’s a bloodbath / and it’s going to get worse before it gets better,” as if it a were mid-tempo folk anthem.

“Hymn and Her” doesn’t achieve that degree of stylized disquiet throughout, but Earlimart’s superficially user-friendly pop is all the more beguiling for the dark recesses hidden inside the whimsical melodies.