Independent rapper Childish Gambino continues to expand on the term concept album with his newest double album “STN MTN / Kauai.”

It continues the story of The Boy, the through line to Gambino’s albums since last year’s “Because the Internet,” a character who was presumed dead by the end of his last album’s story line. This assumption drives the belief that “STN MTN / Kauai” takes place earlier in The Boy’s story.

“STN MTN / Kauai” is split into two parts, each side’s theme reflecting their respective title. The “STN MTN” side is a hip-hop oriented mixtape centering on The Boy’s dream of running Atlanta, hosted by DJ Drama, the title referring to the Stone Mountain area where Childish Gambino grew up in Atlanta, Georgia. While the “Kauai” side is an R&B and pop inspired EP, featuring Jaden Smith as The Boy, named after Kauai, Hawaii.

In an interview with Childish Gambino, Hot 97’s Peter Rosenberg said Gambino’s mixtape collaboration with DJ Drama was “an unlikely pairing” and likened it to the uniqueness of Pharrell’s 2006 release with DJ Drama, “In My Mind (The Prequel).”

Rosenberg is correct, as Childish Gambino takes full advantage of the mixtape format with “STN MTN” by selecting an unexpected set of songs. More than half of the mixtape sees Gambino rapping over other artists’ beats and reworking songs that would, in any other context, cost too much to license. This includes better known works, like Future’s “Move that Dope” and Lil Wayne’s “Go DJ,” and more obscure songs like Timbaland and Magoo’s “All Y’all.”

Gambino maintains his sense of authorship by making each song his own while retaining elements of the songs being used. For instance, his “Move That Dope” reworking begins with him adapting Future’s opening lines, “whippin’ the Lam’, whippin’ and grippin’ the Lam,’” and continuing with his own verse, a verse that was previously used as a freestyle at this year’s Lollapalooza music festival.

His best reworking on “STN MTN” is a cover of Usher’s Neptunes produced “U Don’t Have to Call.” It begins with Childish Gambino singing a cappella until a keyboard reworking of the beat comes in, courtesy of Gambino’s frequent production collaborator Ludwig Goransson, and builds from there. The song ends with a spoken word verse where Childish Gambino describes his his personal story and heritage.

The puns and double entendres are toned down here in favor of one-liners which puts more emphasis on the few, poignant moments of “STN MTN.” Moments whose impact are darker than expected, like on the chorus for “Nextel Chirp” where he discusses the setbacks of his cousin, “yeah, my cousin used to serve him, now he learning how to walk.”

What endures “STN MTN” is Childish Gambino’s delivery. It’s his energy and vocal flourishes that carry the mixtape through the occasional, uninspired line.

But, the “Kauai” side of “STN MTN / Kauai” is the opposite of the former in theme and execution.

Prior to the EP’s release, Childish Gambino told Rosenberg, in the same interview, that he felt hip-hop has evolved to fully incorporate pop music. This sentiment is evident across “Kauai” and was likely reaffirmed by his success with “V. 3005” from “Because the Internet.”

The “Kauai” side has a more coherent sound and theme than “STN MTN.” It feels aesthetically like Hawaii, something that you’d play at the beach, with catchy chorus to match.

Songs like “The Palisades” strike a good balance between simple choruses and good imagery, as Gambino simply repeats “love don’t really happen” in a matter-of-fact way. He continues over the song’s bouncy, guitar strumming beat with the verse “Now why can’t every day be like this/smoke a J at the beach like this/hang with bae at the beach like this/conversations with Kish like this.”

Childish Gambino’s development as an artist since he hit his stride with his 2010 mixtape “Culdesac” is emphasized on “Retro” which is a reworking of his own song, “Love Is Crazy,” off of his debut 2008 mixtape. The new lyrics, over the song’s original beat, show more maturity in his writing and confidence in his singing ability.

The presence of Jaden Smith, who delivers two poems on “Pop Thieves (Make It Feel Good)” and “Late Night in Kauai,” is the only weak point of the seven tracks that make up “Kauai.” His presence as The Boy works as a concept, but fails in its execution. Smith’s two poems never quite connect.

But, the latter track does see Childish Gambino delivering his most focused rap verse across all of “STN MTN / Kauai.” He utilizes his sense of whimsy while calmly delivering lines like, “balling like Jabari Parker, they say I look like him/if we met I bet it would be awkward” and “I’m in the mood so we can ball out/got the top down in the back we could fall out.”

Overall, “STN MTN / Kauai” is an interesting concept with unique execution. Had the mixtape and EP been released separately, the former’s flaws would be so glaring, as the clarity of what the “Kauai” side is trying to accomplish makes “STN MTN” look hectic. But, this too could be a conscious decision from Childish Gambino as he said in the same interview with Rosenberg, “being young and black in America is schizophrenic,” which he wants “STN MTN / Kauai” and the story of The Boy to reflect.