At the advent of Technicolor, movie posters were plastered with enthusiastic phrases like “Technicolor Triumph,” and “Now in brilliant Technicolor!” Iron & Wine’s discovery of musical instruments beyond the guitar inspires a similar degree of zeal: “Now with sitar and piano!” ought to be branded on the cover of the album.

Iron & Wine’s personal, lo-fi, solitary-man-with-a-guitar intimacy had a power of its own. But after listening to “The Shepherd’s Dog,” the previous albums sound almost anemic by contrast.

Iron & Wine — part of the one-man band phenomenon that includes artists like The Mountain Goats and Cat Power — is actually just singer-songwriter Sam Beam. This element was played up in his early work, which he recorded alone. Prior to “The Shepherd’s Dog,” Beam’s music has been characterized by minimal instrumentation, usually just an acoustic guitar or banjo. Combined with intensely personal lyrics, Iron & Wine was a lesson on how to be alone.

Although an acoustic guitar still leads Iron & Wine’s songs, the additional instrumentation gives the tracks texture, making the lack of dynamics less noticeable. “Boy With a Coin,” the first single off the album, illustrates this evolution well. Beam’s multi-tracked vocals and drum claps, though recorded alone, imply the presence of the multiple people absent from Iron & Wine’s previous albums.

“The Shepherd’s Dog” sounds like it follows the logical progression of Beam’s solo career. From the fuzzy, demo-tape-quality lullabies of Iron & Wine’s debut album, “The Creek Drank the Cradle,” to the produced, more articulated “Our Endless Numbered Days,” the next step was to expand both in musical complexity and lyrical themes.

The lyrics remain poetic and oblique, with occasional bursts of lucidity, like those of “Innocent Bones”: “And even the last of the blue-eyed babies know / That the burning man is the color of the end of day / And how every tongue that gets bit always has another word to say.”

Beam has expanded his subjects, however, from the gothic, alien stories of childhood and love to more political, reality based subject matter. Beam’s incomprehension of American politics is most expressed on the track “White Tooth Man,” with the lyrics, “And the white tooth man who sold me a gun / A map of Canaan and a government bond / Said, ‘I love this town, but it ain’t the same.’” On tracks like “Innocent Bones,” however, the familiar themes of longing and disappointment return in the shape of references to Cain and Abel.

Between the familiar and new, though, falls the best song on the album, “Resurrection Fern.” With the plucked guitar, shaker and lyrics like, “In our days we will live / Like our ghosts will live,” it strikes the right balance between melancholy and romanticism.

Although the leap from the previous album to “The Shepherd’s Dog” may require a few listens before Iron & Wine fans appreciate the change, Beam may bring more listeners into the fold with the album’s increased accessibility and greater sonic variety.