The origins of Indian music can be traced back to the Vedic literature of Hinduism and the ancient Natyashastra, the classic Sanskrit text on performing arts by Bharata Muni. The earliest Indian thought combined three arts, syllabic recital (vadya), melos (gita) and dance (nrtta), and as these fields developed, sangeeta became a distinct genre of art, in a form equivalent to contemporary music. The music tradition in India is based on a combination of seven notes, named as the Saptaswara, which are Sa, Ri, Ga, Ma, Pa, Da, Ni. Indian classical music is generally passed down in an oral tradition where the student would spend many years with their ‘guru’, developing a very special, spiritual bond, imbibing all aspects of the music along with philosophical and moral principles that shape them for life. Indian classical music has historically adopted and evolved with many regional styles, such as the Bengali classical tradition, and this openness to ideas led to assimilation of regional folk innovations, as well as influences that arrived from outside the subcontinent.