Alabama Shakes shake up their sound

3 stars (out of 4)

In 2012, when Alabama Shakes released its debut album, “Boys & Girls,” the studio was not the band’s friend. Songs that popped in concert sounded relatively constrained on record. The melodies were strong but fell into a retro pocket, evoking soul and roots-rock dynamics from the ’60s and ’70s. Brittany Howard’s towering voice was undeniable, however, and “Boys & Girls” became one of the year’s most acclaimed albums because her intensity melted a lot of quibbles about the lack of genuine surprise in the arrangements.

Howard’s voice is more formidable than ever on the follow-up, “Sound & Color” (ATO). Now she sounds like a different vocalist on virtually every tune. On the title track she evokes the dreamy drift of ’70s Marvin Gaye, “Don’t Wanna Fight” struts and wheezes with James Brown-like bravado, “This Feeling” channels doo-wop and finger-snapping swing, and “Future People” is almost operatic in its upper-register longing. She imbues the music with a lonesome shiver, frequently singing at the top edge of her voice. But when she drops down an octave or more, her voice becomes a howl, and “Gimme All Your Love” transforms a plea into a demand.

“Sound & Color” also lives up to its title as an exploration of the studio as an instrument. With the help of relatively unsung producer Blake Mills, the Shakes shift the focus away from decades-old structures into a shiftier blend that blurs lines between genre and era.

The band’s Southern-soul roots haven’t been entirely abandoned. “Future People” repurposes the riff from Booker T and the MG’s “Time is Tight,” and the slow-burn “Miss You” suggests a lost Otis Redding ballad, if not the second cousin of the Shakes’ first-album scorcher “You Ain’t Alone.” Keyboards play a bigger role in creating a new sonic architecture, whether the sci-fi wiggle of “Gemini” or the psychedelic shimmer of “Sound & Color,” and the rhythm section veers from the mid-tempo country-soul reliability of the debut to explore more abstract, orchestral coloring. The guitar interplay between Howard and Heath Fogg becomes less genre-specific, particularly with the thrilling bends in “Dunes,” delicate groove of “Guess Who” and punkish thrust in “The Greatest.”

Howard’s lyrics aren’t nearly as ambitious. She sings of turmoil and irresolution, but keeps the details to herself. The drama is all in the way she uses her voice - the key instrument on an album brimming with new Shakes sounds and colors.