This month’s absolute must-have is Separate Cages (Alchemy ALCD 1007; 58:23), a collection of tightly constructed, intimate guitar duets by Wayne Krantz and Leni Stern. The duo spins detailed and nuanced “conversations”-from the melancholy, overtone-driven tone painting of Stern’s “Leave Softly,” to the dark, bluesy rock tones of Krantz’s “Claudine,” with Stern on dobro. Krantz’s “Nicole” features a beautifully executed point-counterpoint between his dizzyingly fast-paced, dark background and Stern’s long-lined, pining solo. The best of these pieces generate palpable emotion-where “November”‘s soft-touch, musing solo and light-toned accompaniment is sad, powerful and full of regret, the duo’s interpretation of Larry John McNally’s “Something is Wrong in Spanish Harlem” is hopeful and gentle, with a smoky vocal by Stern (“if music has the power to change things/even in the smallest of ways/I send these notes to the night/like a prayer to the light”). McNally’s heartening lyric is at the emotional center of this fine, thought-provoking effort.