Music in the East was based on ragas, which means a certain arrangement of notes, a theme which was recognized and distinguished as a certain raga. These ragas were composed by four different classes of people: by those who studied and practiced folk-songs, and out of these folk-songs arranged certain themes or ragas; by mathematicians who mathematically worked out many hundreds of ragas; by poets and dramatists who composed ragas and their wives, raginis, as well as sons, daughters, and daughters and sons-in-law, creating in this way families of ragas in their imagination; and finally by musicians who out of the three above mentioned kinds of ragas composed new ones with their musical gift. On these ragas the music of India was based.