Alabama Shakes started out playing covers at local gigs but quickly found a unique personal voice rooted in rock and soul. The band came to national attention, found a wide and devoted public, and soon earned four Grammys, for the album “Sound and Color.” But after that record, their second, Brittany Howard—who sings, plays guitar, and writes songs for the group—announced that she was putting Alabama Shakes on hiatus, to work on a solo album. “We sat and we talked about it for several hours; we sat in a circle,” she recalls. “At the end of the conversation, everybody was, like, ‘O.K., we understand. We get it.’ They gave me their blessing to go on and find what I needed to find or create what I needed to create.” Howard gathered a different group of musicians, including the keyboard superstar Robert Glasper, to back her up on a solo album, called “Jamie.” It’s named after Howard’s late sister, but it’s very much about the singer herself—her passions, her concerns, and her upbringing, in Athens, Alabama. Is this, David Remnick asks, the end of Alabama Shakes? “I don’t know,” Howard says, after a pause. “Wherever creativity leads my ship, I can’t force it. That’s the thing. Once I start forcing it, it’s not going to be no good, anyway.”