Modern Standard Hindi is, as literary languages go, young. It was standardized in the nineteenth century on Khari Boli, the speech of the Delhi region, written in the Devanagari script and consciously furnished with a Sanskrit derived vocabulary, and it became the official language of independent India in the twentieth. But the devotional culture it carries is old, and Hindi stands as the modern heir of a family of North Indian literary languages that had already sung for centuries.
The Braj Bhasha of the Krishna poets, the Awadhi of Tulsidas's Ramcharitmanas, and the mixed idiom of the sant poets such as Kabir all flowed into the region's shared devotional inheritance, and modern Hindi speakers receive Surdas, Tulsidas, Mirabai and Kabir as their own classics, printed in Devanagari in Hindi anthologies even though their languages differ from the modern standard. The result is a devotional register with unusual depth of field, a modern standardized language behind which stand five centuries of bhakti verse that remains fully alive in performance. A Hindi speaker at a temple aarti or a kirtan gathering moves without effort between compositions of the sixteenth century and the twentieth, and the modern language's own devotional production, from printed prayer books to film bhajans, continues the line without a break.