By almost single-handedly adapting slide guitar to classical Indian music, Debashish Bhattacharya not only expanded the possibilities of the instrument, but widened the scope of his country’s traditions. When Bhattacharya is deep into a raga, it’s easy to forget that he’s not plucking at a sitar, so seamlessly has he integrated the guitar with the form. But he’s never been a strict traditionalist he’s always looking to turn down a new road, and with Calcutta Chronicles, Bhattacharya has crafted his definitive work. Album opener “Sufi Bhakti” incorporates a slide ukulele as well as tabla and the one-stringed ektara, while Bhattacharya goes it alone on the celestial/spiritual journey “Kolkata To Kanyakumari.” On “Gypsy Anandi,” the slide’s Hawaiian roots are never far from the surface, even as the underlying rhythm suggests an African influence and a Roma spirit. But “Aviskaar” is the album’s crown jewel—a hypnotic raga that brings to mind Ravi Shankar’s defining works of the ’60s and ’70s. It’s Indian classical music both as it was meant to be played and has never been played before.