A Thaat () is a "Parent scale" in North Indian or Hindustani music. The concept of the "thaat" is not exactly equivalent to the western musical scale because the primary function of a "thaat" is not as a tool for music composition, but rather as a basis for classification of ragas. There is not necessarily strict compliance between a raga and its parent "thaat"; a raga said to 'belong' to a certain "thaat" need not allow all the notes of the "thaat", and might allow other notes. "Thaats" are generally accepted to be heptatonic by definition.