Many of the concepts of Indian music commonly prevalent in Bharata's time, and expressed quite succinctly in his Nāṭyaśāstra, have subsequently been confused by later writers. Even now, several modern writers are still in some doubt as to the nature of the ancient parent scales, the sa-grāma and the sa-grāma. The fundamental difficulty hinges around the location of the svara (note) in relation to its śrutis (component intervals). Contrary to Western practice, the interval is considered to precede the note, so that the four śrutis of sa are located between sa and the ni below it.