Bollywood films are generally musicals, and are expected to contain catchy music in the form of song-and-dance numbers woven into the script. A film's success often depends on the quality of such musical numbers. Songs from Bollywood movies are generally pre-recorded by professional playback singers, with the actors then lip synching the words to the song on-screen, often while dancing.
Most notable singers of Bollywood are Suraiyya, Noor Jehan, Lata Mangeshkar, Asha Bhosle, Geeta Dutt, Shamshad Begum, Alka Yagnik, etc among female playback singers and K. L. Saigal, Talat Mahmood, Mukesh, Mohammed Rafi, Manna Dey, Hemant Kumar, Kishore Kumar, Kumar Sanu, Udit Narayan, Sonu Nigam among male playback singers.
Remixing of film songs with modern beats and rhythms is a common occurrence today, and producers may even release remixed versions of some of their films' songs along with the films' regular soundtrack albums.
