The idea sounded promising. Sleater-Kinney, the three-woman band that arose from the riot grrrl movement to make smart, knotty, engaged, passionately ambitious indie rock, was getting produced by Annie Clark, better known as St. Vincent, a songwriter with startling ideas and constantly shifting guises. The result is “The Center Won’t Hold,” an album that all but jettisons Sleater-Kinney’s longtime musical identity.

It’s an unexpected expansion of Sleater-Kinney’s musical vocabulary and a bold swerve in the direction of pop. Unfortunately, most of the time it’s a wrong turn. On July 1, Janet Weiss — Sleater-Kinney’s catalytic drummer since 1996 — announced that she was leaving the band as it is “heading in a new direction.”

From its formation in 1994, Sleater-Kinney’s music has been defined by the gnarled interplay of Carrie Brownstein’s and Corin Tucker’s guitars: sometimes meshed, sometimes overlapping, sometimes at cross-purposes, sometimes intricate, sometimes noisy. But on the new album, the guitars are constrained, ceding space to keyboards and electronic beats; often, they’re content to repeat neatly deployed hooks. Instead of tense, fluctuating human friction, there’s layered pop architecture.