Tagore's poetic style, which proceeds from a lineage established by 15th- and 16th-century Vaishnava poets, ranges from classical formalism to the comic, visionary, and ecstatic. He was influenced by the atavistic mysticism of Vyasa and other "rishi"-authors of the Upanishads, the Bhakti-Sufi mystic Kabir, and Ramprasad Sen. Tagore's most innovative and mature poetry embodies his exposure to Bengali rural folk music, which included mystic Baul ballads such as those of the bard Lalon. These, rediscovered and repopularised by Tagore, resemble 19th-century Kartābhajā hymns that emphasise inward divinity and rebellion against bourgeois "bhadralok" religious and social orthodoxy. During his Shelaidaha years, his poems took on a lyrical voice of the "moner manush", the Bāuls' "man within the heart" and Tagore's "life force of his deep recesses", or meditating upon the "jeevan devata"—the demiurge or the "living God within". This figure connected with divinity through appeal to nature and the emotional interplay of human drama. Such tools saw use in his Bhānusiṃha poems chronicling the Radha-Krishna romance, which were repeatedly revised over the course of seventy years.