You can’t fault a guy for finding his niche. But after three successful albums, Jack Johnson has done so well pigeonholing himself there’s little left to listen for.

Since his surprise hit debut, Brushfire Fairytales (2002), his intensely hummable acoustic delights filled with quirky phrasings, head-bopping percussion and melodies your mother could love have become a dorm room staple. But they’ve always been a little too close for comfort. Johnson’s sound has become so monotonous that you could set your iPod to shuffle and play his entire repertoire without knowing which song came from which album.

But to Johnson’s credit, neither diversity nor musical complexity was ever his M.O. – his music is tailored for backyard barbecues, not critical assessment. It is meant for easy listening and never fails at that. The former professional surfer seems so relaxed that engaging the listener often becomes somewhat of an afterthought.

That should not be the case on Johnson’s latest effort. Enlisted to pen the soundtrack for the upcoming film Curious George (set to release Feb. 10), the artist finds himself in a slightly new position – becoming the voice of a voiceless children’s character.

Where some may see this role as a challenge, for Johnson it is only an opportunity to expand his wide-ranging audience. If you’re accessible enough to attract the Top 40, alternative and adult contemporary markets, why not play your hand at the Raffi scene, too? But while Sing-A-Longs and Lullabies for the film Curious George fits the bill for the movie and even features its share of hits, Johnson forgoes the opportunity to explore new territory and instead falls back on his laurels, resulting in far less enticing material than any of his previous releases.

Johnson is joined on the album by longtime friends Ben Harper and G. Love, as well as newer musical cohort Matt Costa, who are featured on one song each. Guitarist Kawika Kahiapo also guests.

A reworked version of “With My Own Two Hands,” a song that originally appeared as the lead track on Harper’s 2003 release Diamonds on the Inside, packs little of the tune’s original punch. The once reggae-tinged song filled with organ solos and wah-wah’d guitar, not to mention Harper’s stunningly expressive voice, is little more than a shell of the former version. It now sounds more like a church hymn with slow finger picking, mismatched harmony and cliche lyrics such as “I can change the world/With my own two hands.”

Johnson does hit the mark midway through the album on a pair of covers: the White Stripes’ “We’re Going to be Friends” and De La Soul’s “The Magic Number” (here known as “The Three R’s” for reduce, reuse and recycle). The songs are as enjoyable for kids as they are for adults – it’s Johnson’s own Schoolhouse Rock.

If it’s possible to hear a song and envision it on-screen, then the album’s closer, “Supposed to Be,” is the perfect credit-roller.

Imagine a heartwarming ending scene featuring an embrace between our young monkey friend and the man in the yellow hat. The camera pans out to a shot of the big city and – BOOM! Cue piano.

Starting with only Johnson’s honey-thick voice and a few sparse chords, the song develops into an emotional quest as Johnson asks, “Maybe this is how it’s supposed to be?” before the fading rally cry: “Being here is so easy to do/If you want to/If you want to.” Not quite Shakespeare, but it gets the job done, a little like Johnson himself.

Contact reporter Zak Garner at zgarnerdbk@gmail.com.