Indian classical music is the classical music of the Indian subcontinent. It has two major traditions: the North Indian classical music tradition is called Hindustani, while the South Indian expression is called Carnatic. These traditions were not distinct until about the 16th century. During the period of Islamic rule of the Indian subcontinent, the traditions separated and evolved into distinct forms. Hindustani music emphasizes improvisation and exploring all aspects of a raga, while Carnatic performances tend to be short and composition-based. However, the two systems continue to have more common features than differences.