Side projects can offer established musicians the freedom to pursue other interests and explore other approaches. The trio Puss N Boots is made up of Norah Jones, Sasha Dobson, and Catherine Popper, who’ve built their reputations on sophisticated strains of jazz-pop, singer-songwriter, and roots-rock fare. Jones is particularly well-known for performances of sultry warmth and thoughtful moderation. But in teaming up, they make room for more notional, permissive, playfully conspiratorial music-making. On their self-contained second album, Sister, they animate rough sketches of ideas, swapping instrumental and vocal roles on originals and covers alike. The album opens with the melodic surf rock noodling of the instrumental “Jamola.” Jones often leads the group into sauntering country territory (see: “It’s Not Easy,” “You Don’t Know,” a ruminatively bluesy rendition of Dolly Parton’s “The Grass Is Blue”). But the three collaborators also summon plenty of bite, from the surly, laconic ’90s alt-rock guitar stylings of “Nothing You Can Do” and “The Great Romancer” to the rankled riff rock of “Same Old B******t” and the lightly bopping garage pop of the title track.