Though he’s played a central role in the world of indie rap in recent years, MC Slug is not entirely convinced of his own worth as an artist. People accuse him of dumbing his raps down, he’s recently said, so his latest album with his duo Atmosphere, When Life Gives You Lemons, You Paint That Shit Gold, is a self-conscious attempt to be more literary. Given that it’s built on narratives that largely aren’t based on Slug’s life, it’s a fairly drastic departure. On 2001’s Lucy Ford: The Atmosphere EP’s, he fixated on a dysfunctional relationship; on 2002’s God Loves Ugly he focused on his own shortcomings (aesthetic and otherwise); and on Atmosphere’s previous album, 2005’s You Can’t Imagine How Much Fun We’re Having, Slug reminisced about his past, spun a heartfelt letter to his young son, and took on political themes. This time around, though, he’s working in a fictional mode, telling stories about waitresses, single mothers, heroin junkies, homeless men, and young girls—mini-biographies he invented while sitting at a bus stop near his Minneapolis home and watching the people in the cars driving by. The sympathetic vagrant of “The Waitress” nurses a crush on a pretty server: “In front of everyone she calls me bum/But she notices my absence/On them afternoons I don’t come,” he raps. The junkie’s enabler in “Shoulda Known” is less sympathetic (and compelling), but “In Her Music Box” is a touching tale of a young daughter infatuated by her ne’er-do-well father: “At the car wash they treat him/Like the star that she sees/They like poppa’s big wheels/And the lollipop she gets/Makes her feel like a big deal.” A pair of guest appearances bolster the album’s serious mood: TV on the Radio’s Tunde Adebimpe sings on “Your Glass House,” and Tom Waits beatboxes on “The Waitress.” (The latter collaboration was organized by one of Waits’ sons, who’s pals with Slug.) The music on the new album is as much of a departure as the lyrics. Producer Ant has largely abandoned sampling others’ records in favor of creating his own sounds; for each track he either wrote the guitar, bass, synth, or trumpet parts and directed the players, or else played a sample and asked the musicians to re-create it. That makes for a more organic-sounding Atmosphere album than its predecessors. That also means that none of the new tracks have the power of a track like “The Arrival” from You Can’t Imagine How Much Fun We’re Having, and without the bangers or the confessionals, When Life Gives You Lemons, You Paint That Shit Gold doesn’t have an immediate payoff. But give it time: There’s lots to like in the duo’s different yet still considered and craft-conscious work.

Atmosphere plays the 9:30 Club Tuesday, April 29.