Also known as Filmi or Hindi Movie Music, Bollywood music is essentially the soundtrack music to Indian popular movies. Bollywood is a combination of the words "Bombay" and "Hollywood" which represents how Bombay, the original name of the city now known as Mumbai, is the film capital of India much like Hollywood is the film capital of the United States. The songs of Bollywood are usually sung by the most talented singers in India of the time of the movie's creation. Bollywood films are filled with the entire spectrum of emotions from utter depression and loss, to uninhibited passionate joy and the music created by Bollywood composers is meant to reflect the emotions being expressed on screen. During the first part of the 1930s, as the Indian film industry moved from silent films to talkies, Bollywood music and dance numbers were incorporated into Indian film. Most of the people who were initially involved in creating Bollywood compositions were from Indian urban theater traditions. Bollywood music was greatly influenced as a result, and even used many of urban theater songs that contained a mixture of Indian classical, light-classical, and local folk music traditions. During the mid 1930s, Bollywood was being heavily influenced by Hollywood and began experimenting with Western instruments, harmony and orchestration. By the 1940s Bollywood composers were including jazz styles, waltzes, and other Western or Latin American influences in their music. Since this time, Bollywood music has continued to experiment with and include foreign musical instruments, structures, and styles in their music based on traditional Indian music. Since Bollywood music was created, it has become very popular and can be heard outside of Bollywood movies in every day life. Composers of Bollywood music have used many of the traditional instruments used in Indian Classical Music. They have also used and experimented with foreign instruments, particularly the guitar because it can be played using a slide to sound much like the Indian Sitar. Today, Bollywood music has permeated Indian culture; it can be heard in almost any public space. It is played at home, in bazaars, on buses, and anywhere else where music is enjoyed. It has become particularly popular for weddings to include Bollywood song and dance numbers as part of their celebration. It is played in formal and informal situations among the varying social classes of India.