According to Indian film director Mahesh Bhatt, Bollywood music is the soul of the movie. It moves the story along and brings people to the theatres.
As Bollywood movies vary in emotion, from dramas to comedies, so does its music. Bollywood music ranges from marriage songs to traditional instrumentals to karaoke and is sung in languages like Hindi, Panjabi and many more.
Musical directors in the early Bombay film industry were interested in classical music, according to the authors of "Global Bollywood: Travels of Hindi Song and Dance." They readily promoted the amalgamation of eastern and western music.
According to Gregory D. Booth in "Behind the Curtain: Making Music in Mumbai's Film Studios," Hindi film music is the closet thing Indian has to popular music, as Hindi films have been the largest component of the national output since 1931.
According to a report in Business Standard, Bollywood music is gaining popularity on global legal music sites. In 2008, 17 of the top 100 world music downloads on iTunes were Bollywood songs.
Most Bollywood music is pre-recorded. Actors and actresses lip-synch to the music during filming. The playback singers receive prominent billing, however, and often have their own followers.