The two well-known classical forms of Indian music are Hindustani and Carnatic music. Hindustani classical music, practiced in North India, features improvisation and long, expressive performances of ragas. Carnatic music, dominant in South India, is more structured with pre-composed pieces and devotional lyrics. Both forms have rich histories, spiritual depth and are taught through oral tradition by gurus to disciples, maintaining their authenticity and cultural importance in the Indian music tradition.