Alka Yagnik is responsible for Shreya Ghoshal's career; Alka refused to perform until Sanjay Leela Bhansali paid her in advance.

Lata Mangeshkar took over for Noorjehan. Geeta Dutt by Asha Bhsole, and Alka Yagnik by Shreya Ghoshal. Here's how: Alka Yagnik ruled the female-playback singing arena at the end of the 1990s and the beginning of the 2000s. Alka was number one after Lata Mangeshkar and Asha Bhosle. An incident occurred while recording a duet with Udit Narayan for Sanjay Leela Bhansali's Hum...Dil De Chuke Sanam that changed Alka's fortunes. 

She refused to record the song, according to eyewitnesses, until she was paid in advance. According to an eyewitness, “Sanjay Bhansali’s production team was short on cash that day. They requested she defer the payment for a few days. To everyone’s shock Alka refused point-blank. ‘Paise nahin toh gana nahin,’ were her words. Of course the cash was arranged somehow. And she sang the duet ‘Chand Chupa Baadal Mein’ with Udit Narayan, and went away with her money. But that was the end of Alka in Bhansali’s cinema.”

Alka Yagnik was supposed to perform all of Hum....Dil Chuke Sanam's songs. But she only sang one song. Kavita Karishnamurthy handled the rest.

Sanjay Bhansali was determined to find a voice in the Lata Mangeshkar mould to replace Yagnik for his next film, Devdas. This was the first time Shreya Ghoshal met Sanjay Bhansali.

“Bhansali immediately sensed her talent, began grooming and modulating her voice, working on her Bengali diction, etc.,” according to source. 

As they say, the rest is history.