During her 12-year career crafting and covering songs, Toshi Reagon has always kept her fans guessing. Here she reaches back a few decades for a fistful of ’60s folk, and with her band, Big Lovely, she marries P-Funk-style riffage with spacy Sgt. Pepper–esque fadeouts and hypnotic blues moans. Reagon and guest Mark Anthony Thompson (of Chocolate Genius) even duet on the Cars classic "Just What I Needed," recontextualizing the ’80s new-wave pop nugget as a gently whispered paean to once-in-a-lifetime love.

This genre-hopping 13-song set does have one recurring theme: the idea of harnessing one’s hope in the midst of pain and injustice. It’s a mantra Reagon absorbed while listening to (and in some cases producing), Sweet Honey in the Rock, the a cappella group her mother, Bernice Johnson Reagon, founded. Just as her mother blended music with socially minded messages, so the punchy classic rock in "Little Light" is all dressing for the activist chant "Will you be there?" Reagon yells it imploringly while meaty guitar licks drive her infectious ardor home — she could fill a freight train with her unflagging optimism. This singer-guitarist truly believes in the power of a little concept called justice, and her fiery pop does its best to make sure her listeners will too.

(Toshi Reagon performs this Friday, June 21, at the Iron Horse in Northampton. Call 413-584-0610.)