Nulo Gopal — born Gopal Krishna Bhattacharya — was a working vocal teacher in 1870s–80s Calcutta, remembered today almost entirely through a single documented episode: he took in the ten-year-old runaway Allauddin Khan as a pupil around 1877 and drilled him in sargam and khyal for seven years, until his own death in a plague outbreak cut the apprenticeship short of its intended twelve. Little else of his life or repertoire survived into print, typical of teachers working before Calcutta's recording era.