The Swell Season’s Glen Hansard and Marketa Irglova may have been produced on an indie-pop assembly line, so perfectly do they melt into the genre’s cookie-cutter mold. Cute and foreign? Check — he’s an Irish singer and she’s a Czech pianist. Stars of a sweet, quiet cult film? Check — they were the nameless protagonists in 2007’s Irish musical “Once,” which spawned Oscar-winning hit “Falling Slowly.” On-again off-again tension in the studio? Check — they briefly dated before making the film and subsequently broke up (pay attention to this one, it’s important).

It’s hard not to dwell on the possibility of true-life romance throughout the pair’s disjointed new Strict Joy. Hansard and Irglova take turns supplying the album’s vocals, each singing from a markedly different place; as the album progresses and their lyrics alternate, how not to fantasize it as one long duet, chronicling two sides of a complicated love story?

Hansard has one particularly intense moment of moodiness during “In These Arms,” in which his whispers and understated whines bemoan a failed relationship. Mostly, though, he specializes in cheerful songs of celebration a la “Back Broke” and “Feeling the Pull.” They’re mind-numbingly upbeat, with just-complex-enough background noise and simple, swooping vocals that invoke nothing so much as the jubilation of being free.

In contrast, Irglova puts her songbird to good use with downbeat medidations on sadness like “Fantasy Man” and “I Have Loved You Wrong,” alternating between dreams of an imaginary lover and apologies for the harm she has inflicted on the one sitting next to her. (We assume. And hope.)

The two narratives meld together in the final and best song of the album, “The Verb,” on which the two lament: “I’m tired of fighting she said/ Your words just rattle my head/ All joy escapes in the dark/ And I can’t make this make sense.” It’s OK, guys — we’ve got no problem filling in the blanks.