Indian classical (Hindustani) music has two foundational elements: raga (melody) and tala (rhythm). The raga forms a melodic structure, while the tala measures the time cycle. Unlike the chords and polyphonic compositions of western music, Hindustani music consists of permanent improvisations, but based on around six thousands ragas with some fixed rules.
The music itself goes back to the centuries leading up to Christ's birth, which is the era of the Natya Shastra, the earliest manuscript in which Indian music is described.
Sitar, sarod, sarangi, shehnai, tabla and tambura are the most common instruments of the Indian subcontinent.
The centres of Hindustani music are the big cities of Delhi, Kolkata, Varanasi, and Mumbai, however, until the 20th century, smaller cities with princely courts, such as Jaipur, Agra, and Gwalior, played a major role.