For once, it’s nice to hear a rock band admit when they don’t really know what they’re doing.

Alabama Shakes apparently would have told you just that a year and a half ago, when the quartet first started working on their transformative sophomore album, “Sound and Color.”

“There wasn’t any concept or vision, really, other than we just wanted to be creative and true to ourselves in every sense of what that means,” guitarist Heath Fogg conceded (or bragged might be more like it).

Fans who have heard “Sound and Color” probably are not surprised to hear this. Alabama Shakes earned a 2013 best new artist Grammy nomination and an unforeseeable amount of commercial success with their debut album, “Boys & Girls,” a rather straightforward blend of retro soul and R&B hooks over a foundation of hard-boogying Southern rock.

The hotly anticipated follow-up record, however, turned out discernibly different — adding intrigue to what should already be a unique concert experience Saturday when the Shakes take over the untested Hall’s Island on the Minneapolis riverfront with Father John Misty.

Psychedelic tones and unconventional song structures abound on the new record. Sly & the Family Stone, Curtis Mayfield, D’Angelo and Danger Mouse-anchored rock acts such as Broken Bells are among the fitting comparisons this time instead of Wilson Pickett and the Stax Records stable. “Production fit for a cannabis dispensary,” is how Rolling Stone’s reviewer aptly put it.

Talking by phone last week from his home in Athens, Ala. — an area where the quartet’s members were all raised and still call home — Fogg said the band knew instinctively it was going to change things up when it came time to record again.

“We were all on the same page and decided that we all wanted it to be a successful creative venture for us no matter what,” he said. “If the record was weird and people who liked ‘Boys & Girls’ don’t really get it — if we lose some fans, or it wasn’t as successful in music industry terms — we shared the same mentality what would be a success to us.”

That said, though, Fogg also doesn’t believe the change is really as dramatic as it’s being made out to be.

“A lot of people latched onto certain aspects of ‘Boys & Girls’ that didn’t define us as much as we hoped,” he said.

“I’m not going to deny that ‘Boys & Girls’ has a classic R&B vibe to it, because that’s definitely there and definitely important to us. But there was some exploration and other influences on that record that fall in line with more independent or alternative artists — more experimentation than people seem to remember.”

Straight outta Athens

Alabama Shakes grew out of the high school friendship between frontwoman Brittany Howard and bassist Zak Cockrell, who — like all four members, it seems — really didn’t have much in common besides being music fanatics in a town not exactly overflowing with them.

“[Athens] is one of those towns where, when you reach a certain age, you just want to get out of it and you don’t appreciate it at all,” Fogg explained, counting that as a positive trait in defining the band.

“There’s no music scene in Athens to shape your influences. It makes you realize early on you have to look elsewhere if you want to play music. And it really makes you want to get on tour and get out of there. It gave us a desire to find a way and not just stay here and play in cover bands.”

The band issued a four-song EP in the fall of 2011 that quickly caught the attention of music bloggers and record labels with the sly-grooving working-woman single “Hold On.” By the time the band hit the South by Southwest Music Conference in March 2012 a month before ATO Records’ release of “Boys & Girls,” it was the hottest new act at the festival.

The live shows are really where the Shakes’ buzz took hold, in large part thanks to Howard. She uses her utterly un-rock-starry look to her advantage in connecting with audiences, on top of preacher-like banter and an explosive, Janis-meets-Aretha voice that can rattle cement.

“She’s unexpected to a lot of people at first, and that helps,” Fogg said. “I see it happen every night: She takes a crowd and keeps it in the palm of her hand and has it clinging to her every word. She just has a commanding presence.”

“But she’s super-talented as a singer, too, and even more talented I think as a musician and creative songwriter.”

Two is better than one

Another of the Shakes’ defining traits has been the rhythmic, often raw dueling guitar parts that Fogg and Howard have developed together. You can especially hear it in “Don’t Wanna Fight,” the first single issued off the new record.

“You don’t have to be that great of a guitar player if you have a good partner,” Fogg said with a chuckle. “There’s something I like about two guitars doing what one guitar could probably do, but it’s more interesting to approach it with two.”

The band continues to expand its sound on tour with the addition of three backup singers, which Fogg said was necessary “because of all the stacked vocals on the new record.”

“It’s tough anytime you go out and play a brand-new record that people don’t know yet, but this record especially has its challenges,” Fogg conceded again (or bragged?).

“It’s been going really, really well considering that. We’re sort of relishing the challenge.”