Filmi is Indian popular music, with specific characteristics arising from its use in film soundtracks. Most Indian pop stars sing in some form of filmi, which has multiple subgenres including filmi-ghazal and ghazal-song. Filmi is often said to have begun in 1931, with the release of Ardeshir M. Irani's Alam Ara and its popular soundtrack. Music is an essential component of Indian cinema, perhaps because of India's linguistic diversity, which means that much of the audience could not understand the dialogue no matter what language it is in; thus, music, not being tied to any one language, can express the feelings of the characters even to those who do not speak the language.