The development of playback in 1935 by New Theatres for the film Dhoop Chhaon revolutionalized the Indian Film Music Industry. Now songs could be recorded in the voice of a different singer while picturizing it on a totally different artiste thus being a boon in disguise to those artistes who could not sing. Thus one artist sang the song while another enacted it on screen. Thus slowly more and more people trained in music began to enter the film Industry. The advent of trained singers also gave Music Directors to try and experiment and compose more challenging tunes as they did not have to worry about the limitations of the actors singing their songs. Thus new sounds, newer innovations found their way into Hindi Film music. With his exposure to Western orchestras accompanying silent films, Keshavrao Bhole at Prabhat was the first to use instruments such as the piano, the Hawaiian guitar and the violin in his compositions. In fact in Prabhat's Duniya Na Mane (1937), he even got its lead actress Shanta Apte to sing an entire song in English! Continuing with the trends of innovation in his next film following Duniya Na Mane, Aadmi (1939), V. Shantaram used a multi-lingual song for the first time. The film is about a touching but ill-fated romance between a prostitute and a policeman. The multi-lingual song composed by Master Krishnarao was used as the prostitute, played by Shanta Hublikar, entertains her clients.

Starting from mainly Indian classical music, slowly more and more musical forms were experimented with such as the rich bank of Indian folk music. Folk songs began to be utilized in Hindi Films mainly when scenes were shown of people in their routine life where they are either drawing water from the well or working in the fields. Through films and Hindi films in particular these folk forms began getting a national audience. Perhaps one of the earliest use of using folk music was the Bhatiali or the song of the Bengali boatman by composer Ramchandra Pal in Bombay Talkies' Kangan (1939) .

1941 saw the release of a film, Pancholi Pictures Khazanchi, which was to change the face of Hindi Film Music. By then Music Directors of the 1930s, who had embellished films with their exquisite compositions set in classical ragas, were beginning to sound commonplace. Khazanchi's refreshingly free wheeling music by Ghulam Haider not only took the audiences by storm but also made other music directors sit up and take notice. Khazanchi, combining popular ragas with the rich verve and rhythm of Punjabi folk music, ensured that the Indian film song would never be the same again. Saawan ke Nazaare with the hero and heroine and their groups on cycles was a trendsetter song not only for its liveliness but also for introducing the big bang meeting of the boy and girl as they bang into each other's cycles!

Gradually Hindi Film Music also began drawing from other States of India - from Uttar Pradesh, Kashmir, Himachal Pradesh. Music forms like the Purabi or Pahadi also proved to be extremely popular.

While Folk music from all over India began being used in Indian Film music, surprisingly contribution from Maharashtra and Gujarat and till recently Rajashtan, was negligible. Marathi folk form did not so much succeed in reaching out to Hindi films largely because it stuck to the language. Also a form like the Lawani was a song and style associated with a Marathi courtesan. In Marathi Cinema and Theatre this was class of women who were freer in their sexual behaviour, in their experience of life in general. Therefore while Marathi Cinema made use of Lawanis quite frequently, Hindi Cinema hardly had such a protagonist. In Hindi Films even if such a female protagonist was used then it normally used the Nautanki folk style of dance drama but even this was rare as largely Hindi Films have had women in stereotypical traditional roles. Gujarati music in Hindi Films has largely been confined to either the Devotional song or the Garba song.

The 40s were perhaps the most rapid changing years of the Indian Film Industry as it saw the collapse of the studio system and the freelance system taking over. And as the technique of filmmaking grew so did the concept of film music. With the era of freelancing and playback now becoming an accepted phenomenon, the Industry opened its doors to a new professional breed of musicians and singers. Some of the earliest singers who came to sing in films included Parul Ghosh, Amirbai Karnataki, Zohrabai Ambalewali, Rajkumari, Arun Kumar, G.M. Durani and Shamshad Begum. Thus the 1940s also saw the decline of the singing star as now established singers sang for actors. Only the established and the best of the singing stars of the 1930s continued singing their own songs - Kanan Devi, Surendranath and of course Kundan Lal Saigal who just seemed to go from strength to strength.

By then the film industry had become more and more fragmented into small production units. Also in this period while active producers multiplied, there was no corresponding increase in exhibition outlets. The days when an exhibitor feared he would not have films to show were gone. Fear had shifted to the producer. Would he now have an outlet for his product? Thus power shifted from the producer to distributor and exhibitor. And they knew exactly what they wanted - big stars AND eight to nine hit songs!

Thus even as Hindi Film music was gaining in popularity, thanks to the efforts of distributors, Hindi Cinema particularly in Bombay found its self going the formulaic way as success at the box office meant everything. Even as music began to undergo changes for the better the quality of films underwent changes for the worse. The story was now of declining importance. It was conceived and developed towards exploitation of the star and due to the importance of music the subject with increasing concentration was romance and boy meets girl stories. Dance and songs provided substitutes for lovemaking and emotional crisis.

At the other end of the coin, in the early 1940s the freedom movement had gathered great momentum. But films couldn't directly challenge the British rule for they would then be banned. Thus filmmakers had to find other ways to gather support for Indian Independence. Sohrab Modi released his magnum opus Sikander in 1941. Sikander, known for its rousing battle scenes, while ostensibly based on the great ruler's life actually used his rival, Porus' dialogues to arouse patriotic feelings and National sentiment. Though Sikander got by the Bombay Censor Board, it was banned in many theatres serving army cantonments. But undeterred by this, some conscious filmmakers were determined to do their cause for the freedom struggle and disguise their message in historic films, dialogues and yes even dance sequences and songs! (Door Hato O Duniyawalon Hundustan Humara Hai (Kismet (1943)).

The Indian film Song was by now rapidly on its way to becoming an extremely important art form with every new innovation bringing its share of joy and excitement. At the same time the Indian freedom movement was moving along at full throttle. But even as India was moving towards her Independence, related events were already starting that would shatter the Indian Music Industry forever…