From the outside, 75-year-old Lata Mangeshkar seems to have achieved enough to keep her in a state of bliss for seven lifetimes.

Hers is a voice that has defined much more than just the melodious progression of Hindi cinema. It will take fans centuries to unravel the enigma of her excellence or the extent of her reach within the film industry.

"I'm a very happy person. Nothing bothers me, nothing ever did. Even when I was going through my normal period of struggle at the beginning, I was content. I'd go out there, sing in the studios and come home and play with my dolls," tells Mangeshkar.

Winning her trust isn't easy. But once you do, she surrenders completely.

Aspiring musicians have become superstar-composers only through what at one time was known as the "one-woman industry" within the film industry.

Some have turned on her, trying to promote sub-standard talent just to thumb their nose at her.

I remember a critic wrote 30 years ago that the 45-year-old Lata singing for a 15-year old, Dimple Kapadia, in "Bobby" just wouldn't work. The songs went on to be a huge hit and made Dimple famous!

When she was out of reach for some filmmakers, they invented her doubles... first Suman Kalyanpur, who got to sing chartbusters with Mohammed Rafi like "Aaj kal tere mere pyar ke charche" and "Ajhun na aaye balma saawan beeta jaye" after the original nightingale fell out with him for two years, then Chandrani Mukherjee, then Anuradha Paudwal and finally Alka Yagnik.

When Dharamesh Darshan couldn't get her to sing in "Dhadkan", he got her in through a her voice on the radio singing "Tu mere saath rahega munne" from the film Trishul for Sharmila Tagore.

One of the most ardent Lata fans in the film industry is Sanjay Leela Bhansali.

"I have to listen to her at least for three or four hours a day. She is like that beacon of light in the darkest hour. I hold her songs very, very close to my heart. In one way or another, all my music scores pay a tribute to Lataji.

"In 'Devdas', the song 'Hamesha tumko chaha' was inspired by her exquisite 'Suniyo ji' in 'Lekin'. I feel she's the greatest artiste this country has ever produced.

"We haven't even begun to measure her contribution to Indian cinema. In every era she has set the parameters for beauty, grace and melody. I hero-worship three people - Amitabh Bachchan, Birju Maharaj and Lata Mangeshkar."

It would be the simplest thing in the world to say Lata is a phenomenon. But her talent isn't easy to slot.

I tell her how Kathak exponent Pandit Birju Maharaj was flabbergasted over her ability to achieve the absolutely rare mixture of contrasting styles in the song "Mohe panghat pe nandlal" in "Mughal-e-Azam".

"I myself don't know what I have done in that song," she bursts out laughing. "People ask me, 'How did you do that particular twist in a song?' or 'How did you put in that bhav (emotion) in that song?' Very frankly I've no answer to these questions.

"I just go and sing to the best of my ability. The rest is entirely up to god."

When you hear her sing love songs like "Lag ja gale" ("Woh Kaun Thi"), "Raina beeti jaye" ("Amar Prem") or "Main janoon nahin piya se milan kaise hoye ri" ("Chand Grahan"), you wonder which beloved she addresses the melodies to. Is it god?

At 75, her divine voice refuses to wane.

Yash Chopra, who loves his 'didi' (elder sister) as much as I do, couldn't have given her and her fans a better birthday gift than "Veer Zaara".

He was advised by his so-called friends and well-wishers to switch to another voice for Preity Zinta. But Chopra was adamant. "As long as I am there and she's there, only Lataji will sing for my films."

Every heroine from Madhubala and Meena Kumari to Aishwarya Rai and Preity Zinta owes her career in varying degrees to Lata's voice.

So many actresses have acquired their legendary status through her songs: Madhubala means "Ayega aanewala" ("Mahal") and "Pyar kiya to darna kya" ("Mughal-e-Azam")... Sharmila Tagore means "Raina beeti jaye" ("Amar Prem") and "Kuch dil ne kahaa" ("Anupama")...

Madhubala, Meena Kumari and Hema Malini would insist that all their songs be sung by only Lata. "Heroines felt they had arrived when Lata sang for them," says Jaya Bachchan, for whom Lata has sung many times.

Where can she go now? "Honestly, I don't know how I've come so far, so how can I say where I'll go now? I let god guide me wherever he wants to. I don't question his ways," says Lata.

Lata remains an awesome force to record with. Even today when she enters at a social gathering, a hush descends in the room. Everyone stops to listen to the melody that she carries in her soul.