Lily Allen, "Sheezus" (Warner Bros.)

Lykke Li, "I Never Learn" (LL/Atlantic)

Beware the third album, otherwise known as the Decider. Among would-be career artists, it's the make-or-break release that separates adult from child, and evolving creator from one-cycle wonder. Think: Prince's "Dirty Mind," Jay Z's "Vol. 2 ... Hard Knock Life," Madonna's "True Blue," Kanye West's "Graduation." Here are two notable third albums, both by artists gunning for stateside pop crossover equal to their homeland success, but approaching the task from wildly varied perspectives.

English hitmaker Allen, 29, best known for her captivating Internet-spawned 2006 debut, "Alright, Still," delivers brash pop incitement on "Sheezus," a dozen seamlessly constructed sonic selfies that are witty, oft-engaging and surprisingly moody. And on "I Never Learn," Swedish singer and songwriter Li, 28, presents a spacious, restrained set of songs that focus on a single love and the fluid ways in which it can evolve. Both feature production work by Los Angeles hitmaker Greg Kurstin (Kelly Clarkson, Kesha), but while Li aims her dynamic, textured voice toward beauty, reflection and stillness with a seeming obsession, Allen works overtime to assure us she's still relevant, hip and insightful even while pretending not to care.

Allen's first album in five years opens with the telling words, "Been here before, so I'm prepared," but she follows that boast with an admirable shot of truth: "Not gonna lie though, I'm kinda scared." Allen seems to be fighting relevancy with every beat, easing into assured comfort only when she ditches topic songs such as "Hard Out Here" (about the double standards placed on female musicians) and "Life for Me" (about social media) to examine less lecture-heavy personal truths. Most infectious — and curious — is the Louisiana zydeco-sampling romp "As Long As I Got You."

Li's moody, sparse album begins with the strum of a 12-string guitar and a moonlit confession directed at a lover and no one else. With a lonely echo and the cavernous feel of a Phil Spector session, Li and producers Kurstin and Bjorn Yttling seem to have been aiming for maximum warmth on "I Never Learn." A compact, nine-song, 32-minute album that suggests an artist just hitting her stride, it seems to have pinpointed the locus of power in her voice. She's at her best on "Love Me Like I'm Not Made of Stone," a forged-from-marble ballad that feels timeless. Featuring a slight, swirling set of acoustic chords and Li's voice at its most dramatic, the song is a hands-and-knees plea from a soul aching for love in its purest form. Throughout the track the sibilant hiss of analog tape hints at a piece intended less for consumption than documentation. "Heart of Steel" sounds recorded in a dungeon, with wood blocks echoing and distant electric guitar lines. Li closes with "Sleeping Alone," a minor-key piano ballad that recalls Big Star's "Holocaust" but without the bitterness.

If history is any guide, the bitterness may come later, after Allen and Li realize America's snobby sense of exceptionalism when it comes to pop music. Which is to say: It gets even more difficult on album No. 4.

Randall Roberts, Los Angeles Times