Ani DiFranco is as well-known for her politics as her candid emotions, and her latest, Knuckledown, dwells more on the latter as she delivers fervent lyrics with her trademark half-whisper, half-gargle. Her focus on the trance-inducing (“Modulation”) and the mellow (“Callous”) culminates in the spoken-word “Parameters,” which winds through DiFranco’s philosophy before returning to her concrete narrative. DiFranco always throws her heart into her songs, and Knuckledown gives her a chance to reflect on it.